System and method for determining operational group assignments of vehicles in a vehicle system

ABSTRACT

A system and method for determining dynamically changing distributions of vehicles in a vehicle system are disclosed. The system and method determine handling parameters of the vehicle system. The handling parameters are determined for different distributions of the vehicles among different groups at different potential change points along a route. The system and method also determine whether to change the distributions at potential change points based on the handling parameters. Based on determining that the distributions are to change, a selected sequence of changes to the distributions is determined at one or more of the potential change points along the route. Change indices are generated based on the selected sequence. The change indices designate times and/or the one or more potential change points at which the distributions changes. The vehicles included in a common group have common designated operational settings while the vehicles are in the common group.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/319,885, which was filed on 30 Jun. 2014 (the “'885application”). The '885 application is a continuation-in-part of U.S.patent application Ser. No. 13/729,298, which was filed on 28 Dec. 2012(the “'298 application”). The entire disclosures of the '885 applicationand the '298 application are incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the subject matter disclosed herein relate to determiningplans for controlling operations of vehicle systems.

BACKGROUND

Some known vehicle systems include multiple vehicles connected togetherso that the vehicles can travel together. Such vehicle systems can bereferred to as consists. Some rail vehicle systems can include multipleconsists that each includes locomotives (or other powered rail vehicles)providing propulsive force.

The operations of the locomotives can be coordinated with each other byremotely controlling some locomotives from another locomotive in therail vehicle. For example, distributed power (DP) control of thelocomotives may involve all locomotives in the rail vehicle system(e.g., a train) being controlled to have the same throttle and/or brakesettings at the same time. Alternatively, the locomotives in a firstconsist of the rail vehicle system may operate with the same throttle orbrake settings while the locomotives in a different, second consist ofthe same rail vehicle system operate with throttle or brake settingsthat are the same, but different from the settings used by thelocomotives in the first consist. In the terminology of currentdistributed power systems, it is said that the fence is set up betweenthe first and second consist.

Because rail vehicle systems may be very long, different segments of therail vehicle systems may experience different grades and/or curvaturesin a track at the same time. Using the same throttle or brake settingsfor multiple locomotives traveling over different grades and/orcurvatures can result in undesirable forces on couplers of the rail carsthat are located between the locomotives and/or undesirable movements ofthe rail cars. For example, when cresting a hill, using the samethrottle settings on all locomotives can cause the rail cars located ator near the apex of the hill to experience relatively large tensileforces, can cause the rail cars on the downward slope of the hill tomove faster than and away from other rail cars at or near the apex,and/or can cause the rail cars on the upward slope of the hill to moveslower than and away from the other rail cars at or near the apex. Theseforces and/or movements can damage the couplers, cause the rail vehiclesystem to break apart, and/or generally degrade handling of the railvehicle system as experienced by an operator of the rail vehicle system.

BRIEF DESCRIPTION

In one embodiment, a method (e.g., for determining operational settingsfor a vehicle system having multiple vehicles connected with each otherby couplers to travel along a route) includes identifying total poweroutputs to be provided by propulsion-generating vehicles of the vehiclesin the vehicle system. The total power outputs are determined fordifferent locations of the vehicle system along the route. The methodalso includes calculating handling parameters of the vehicle system atone or more of the different locations along the route. The method alsoincludes determining asynchronous operational settings for thepropulsion-generating vehicles at the different locations along theroute. The asynchronous operational settings represent differentoperational settings for the propulsion-generating vehicles that causethe propulsion-generating vehicles to provide at least the total poweroutputs at the respective different locations while changing thehandling parameters of the vehicle system to one or more designatedvalues at the different locations along the route. As one example, thedifferent operational settings may be different notch settings ofthrottles of the different vehicles in the vehicle system. Due todifferences in the vehicles, different notch settings on differentvehicles may result in the vehicles individually providing the sameamount of power output. Alternatively, the vehicles may providedifferent power outputs when using the same throttle settings. Themethod further includes communicating the asynchronous operationalsettings to the propulsion-generating vehicles in order to cause thepropulsion-generating vehicles to implement the asynchronous operationalsettings at the different locations.

In one embodiment, a system (e.g., a control system for a vehiclesystem) includes an effort determination unit configured to identifytotal power outputs to be provided by a vehicle system that includesmultiple vehicles connected with each other by couplers to travel alonga route. The effort determination unit also is configured to identifythe total power outputs to be provided by propulsion-generating vehiclesof the vehicles in the vehicle system at different locations of thevehicle system along the route. The system includes a handling unitconfigured to calculate handling parameters of the vehicle system at oneor more of the different locations along the route. The system includesa processing unit configured to determine asynchronous operationalsettings for the propulsion-generating vehicles at the differentlocations along the route. The asynchronous operational settingsrepresent different operational settings for the propulsion-generatingvehicles that cause the propulsion-generating vehicles to provide atleast the total power outputs at the respective different locationswhile changing the handling parameters of the vehicle system to one ormore designated values at the different locations along the route. Theasynchronous operational settings are configured to be communicated tothe propulsion-generating vehicles in order to cause thepropulsion-generating vehicles to implement the asynchronous operationalsettings at the different locations.

In one embodiment, a method (e.g., for determining operational settingsfor a vehicle system having two or more propulsion-generating vehiclescoupled with each other by one or more non-propulsion generatingvehicles) includes obtaining route data and vehicle data. The route datais representative of one or more grades of a route at one or morelocations along the route that is to be traveled by the vehicle system.The vehicle data is representative of a size of the one or morenon-propulsion generating vehicles disposed between thepropulsion-generating vehicles. The method also includes calculating oneor more estimated natural forces that are to be exerted on couplersconnected with the one or more non-propulsion generating vehicles of thevehicle system at the one or more locations along the route. The one ormore estimated natural forces are based on the size of the one or morenon-propulsion generating vehicles and the one or more grades of theroute at the one or more locations along the route. The method alsoincludes determining asynchronous operational settings to be implementedby the two or more propulsion-generating vehicles at the one or morelocations along the route. Implementing the asynchronous operationalsettings by the two or more propulsion-generating vehicles reduces oneor more actual natural forces that are actually exerted on the couplersto forces that are smaller than the one or more estimated natural forceswhen the vehicle system travels over the one or more locations along theroute.

In another embodiment, a method (e.g., for determining dynamicallychanging distributions of vehicles in a vehicle system) includesdetermining handling parameters of a vehicle system that includes pluralvehicles operably coupled with each other to travel along a route duringa trip. The handling parameters are determined for differentdistributions of the vehicles among different groups of the vehicles atdifferent potential change points along the route. In one aspect,changing a distribution of the vehicles among different groups includeslogically changing which group one or more vehicles are assigned towithout actually physically moving the one or more vehicles. This may bedone dynamically en-route or statically at the beginning of a trip.Alternatively, one or more embodiments described herein can be todetermine different distributions of the vehicles among different groupsthat does involve physically moving the vehicles relative to each otherto position the vehicles with each other in the respective groups. Whilethis would typically be statically at the beginning of a trip, there arecases when a vehicle may be added to the system for a portion of thetrip. For example, the vehicle system may stop during travel between twolocations to change locations of vehicles within the vehicle system, toadd one or more vehicles to the vehicle system, and/or to remove one ormore vehicles from the vehicle system.

The method also can include determining whether to change thedistributions of the vehicles among the different groups at one or moreof the potential change points based on the handling parameters that aredetermined and, based on determining that the distributions of thevehicles among the different groups are to change, determining aselected sequence of changes to the distributions of the vehicles amongthe different groups at one or more of the potential change points alongthe route. The method also includes generating change indices for one ormore of the trip or an upcoming segment of the trip based on theselected sequence. The change indices designate one or more of times orthe one or more potential change points along the route at which thedistributions of the vehicles among the different groups changes. Thevehicles included in a common group of the different groups have commondesignated operational settings while the vehicles are in the commongroup.

In another embodiment, a system (e.g., a planning system) includes oneor more processors configured to determine handling parameters of avehicle system that includes plural vehicles operably coupled with eachother to travel along a route during a trip. The handling parameters aredetermined for different distributions of the vehicles among differentgroups of the vehicles at different potential change points along theroute. The one or more processors also are configured to determinewhether to change the distributions of the vehicles among the differentgroups at one or more of the potential change points based on thehandling parameters that are determined and, based on determining thatthe distributions of the vehicles among the different groups are tochange, the one or more processors are configured to determine aselected sequence of changes to the distributions of the vehicles amongthe different groups at one or more of the potential change points alongthe route. The one or more processors also are configured to generatechange indices for one or more of the trip or an upcoming segment of thetrip based on the selected sequence, the change indices designating oneor more of times or the one or more potential change points along theroute at which the distributions of the vehicles among the differentgroups changes. The vehicles that are included in a common group of thedifferent groups have common designated operational settings while thevehicles are in the common group.

In another embodiment, a method (e.g., for determining asynchronousoperational settings of vehicles in a vehicle system) includes obtainingroute data and vehicle data. The route data is representative of one ormore of grades of a route, curvatures of the route, speed limits of theroute at one or more potential change points of the route that is to betraveled by a vehicle system or that is currently being traveled by thevehicle system. The vehicle system includes plural vehicles coupled witheach other. The vehicle data is representative of one or more oftractive efforts of the vehicles, braking efforts of the vehicles, orsizes of the vehicles. The method also includes predicting handlingparameters of the vehicle system at the one or more potential changepoints of the route based on the route data and the vehicle data, anddetermining asynchronous operational settings to be implemented by thevehicles at the one or more potential change points of the route basedon the handling parameters. The asynchronous operational settings aredetermined by identifying a combination of the asynchronous operationalsettings at the one or more potential change points of the route thatresult in the handling parameters being decreased below one or moredesignated thresholds.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings in which particularembodiments and further benefits of the invention are illustrated asdescribed in more detail in the description below, in which:

FIG. 1 illustrates a schematic diagram of one example of a vehiclesystem traveling along a route;

FIG. 2 is a flowchart of one embodiment of a method for operating thevehicle system shown in FIG. 1;

FIG. 3 illustrates coupler parameters that are estimated for a vehiclesystem to travel along a route in accordance with one example;

FIG. 4 illustrates terrain excitation parameters that are estimated forthe vehicle system shown in FIG. 3 to travel along the route also shownin FIG. 3 in accordance with one example;

FIG. 5 illustrates two relationships between different asynchronousoperational settings and a handling parameter at two different locationsalong the route 102 shown in FIG. 1 in accordance with one example;

FIG. 6 is a flowchart of another embodiment of a method for operatingthe vehicle system shown in FIG. 1;

FIG. 7 is a flowchart of another embodiment of a method for operatingthe vehicle system shown in FIG. 1;

FIG. 8 is a schematic diagram of one embodiment of apropulsion-generating vehicle;

FIG. 9 is a schematic illustration of another embodiment of a vehiclesystem;

FIG. 10 illustrates a flowchart of a method for determining commandprofiles and/or change indices that dynamically change group assignmentsof the vehicles and/or fence positions in the vehicle systems shownherein according to one embodiment;

FIG. 11 illustrates a table demonstrating possible sequences of changingthe vehicle group assignments in the vehicle system according to oneembodiment;

FIG. 12 illustrates examples of handling parameters calculated for threedifferent vehicle group assignments or fence positions according to oneembodiment; and

FIG. 13 illustrates a schematic diagram of a planning system accordingto one embodiment.

DETAILED DESCRIPTION

FIG. 1 illustrates a schematic diagram of one example of a vehiclesystem 100 traveling along a route 102. The vehicle system 100 includesseveral vehicles 104, 106 operably coupled with each other. The vehiclesmay be mechanically coupled with each other, such as by couplers 108.Alternatively, the vehicles may be coupled with each other without beingmechanically coupled with each other. For example, the vehicles may beaerodynamically or fluidly coupled with each other when the vehiclestravel sufficiently close to each other that the drag forces imparted onone or more of the vehicles (e.g., from air, wind, water, or the like),is reduced on one or more other vehicles. Marine vessels may be fluidlyor aerodynamically coupled when the vessels travel close enough togethersuch that the drag on one or more vessels from the water is reducedrelative to the marine vessels traveling farther apart. Automobiles(e.g., trucks) may be fluidly or aerodynamically coupled when theautomobiles travel close enough together such that the drag on one ormore automobiles is reduced relative to the automobiles travelingfarther apart. Two vehicles 104 and/or 106 may be directly connectedwith each other when no other vehicle 104 or 106 is disposed between thedirectly connected vehicles 104 and/or 106. Two vehicles 104 and/or 106may be indirectly connected or interconnected with each other when oneor more other vehicles 104 and/or 106 are disposed between and connectedwith the interconnected vehicles 104 and/or 106.

The vehicles 104 (e.g., vehicles 104A-G) represent propulsion-generatingvehicles, such as vehicles capable of generating propulsive force topropel the vehicle system 100 along the route 102. Examples ofpropulsion-generating vehicles 106 include locomotives, otheroff-highway vehicles (e.g., vehicles that are not designed for orpermitted to travel on public roadways), automobiles (e.g., vehiclesthat are designed for traveling on public roadways), marine vessels, andthe like. In one embodiment, the vehicles 104 represent locomotives andthe vehicles 106 represent rail cars. The vehicles 104 may befuel-powered vehicles (e.g., engines that consume fuel are used togenerate propulsive force by creating electric current to power motorsor to rotate axles and wheels), electric-powered vehicles (e.g., onboardor off board sources of electric current are used to power motors togenerate propulsive force), and/or hybrid powered vehicles (e.g.,vehicles that are powered by fuel-consuming engines and other sources ofelectric current). The vehicles 106 (e.g., vehicles 106A-I) representnon-propulsion-generating vehicles, such as rail cars or other unitsthat are propelled along the route 102 by the propulsion-generatingvehicles 104.

The term “vehicle” as used herein can be defined as a mobile machinethat transports at least one of a person, people, or a cargo. Forinstance, a vehicle can be, but is not limited to being, a rail car, anintermodal container, a locomotive, a marine vessel, mining equipment,construction equipment, an automobile, and the like. A “vehicle system”includes two or more vehicles that are interconnected with each other totravel along a route. For example, a vehicle system can include two ormore vehicles that are directly connected to each other (e.g., by acoupler) or that are indirectly connected with each other (e.g., by oneor more other vehicles and couplers). A vehicle system can be referredto as a consist, such as a rail vehicle consist.

“Software” or “computer program” as used herein includes, but is notlimited to, one or more computer readable and/or executable instructionsthat cause a computer or other electronic device to perform functions,actions, and/or behave in a desired manner. The instructions may beembodied in various forms such as routines, algorithms, modules orprograms including separate applications or code from dynamically linkedlibraries. Software may also be implemented in various forms such as astand-alone program, a function call, a servlet, an applet, anapplication, instructions stored in a memory, part of an operatingsystem or other type of executable instructions. “Computer” or“processing element” or “computer device” as used herein includes, butis not limited to, any programmed or programmable electronic device thatcan store, retrieve, and process data. “Non-transitory computer-readablemedia” include, but are not limited to, a CD-ROM, a removable flashmemory card, a hard disk drive, a magnetic tape, and a floppy disk.“Computer memory”, as used herein, refers to a storage device configuredto store digital data or information which can be retrieved by acomputer or processing element. “Controller,” “unit,” and/or “module,”as used herein, can to the logic circuitry and/or processing elementsand associated software or program involved in controlling an energystorage system. The terms “signal”, “data”, and “information” may beused interchangeably herein and may refer to digital or analog forms.

At least one technical effect described herein includes generatingcommand profiles and change indices for a trip of a vehicle system. Thecommand profiles can dictate operational settings (e.g., throttle notchsettings or other settings) of propulsion-generating vehicles in thevehicle system, and the change indices can dictate where and/or whenassignments of the vehicles among different groups and/or fencepositions in the vehicle system are to be changed. The command profilesand/or change indices may be generated before the vehicle system embarkson the trip, generated while the vehicle system is moving along a routeduring the trip, subsequent to completing the trip (e.g., to allow forcomparison with how the operator controlled the vehicle system duringthe previous trip), or a combination thereof. The command profilesand/or change indices may be used to control which propulsion-generatingvehicles in the vehicle system have the same or different operationalsettings (e.g., throttle notch settings) at different locations in thetrip in order to control bunching of the vehicle system.

The propulsion-generating vehicles 104 may be arranged in consists 110,112, 114, as shown in FIG. 1. Each consist 110, 112, 114 may include thepropulsion-generating vehicles 104 directly connected with each other inthe vehicle system 100. While each consist 110, 112, 114 is shown asincluding multiple propulsion-generating vehicles 104, one or more ofthe consists 110, 112, 114 may optionally include a singlepropulsion-generating vehicle 104.

While the vehicle system 100 is shown in FIG. 1 as a train,alternatively, the vehicle system 100 may represent another vehiclesystem formed of vehicles other than locomotives (e.g., thepropulsion-generating vehicles 104) and railcars (e.g., thenon-propulsion generating vehicles 106). For example, the vehicle system100 may represent several automobiles, marine vessels, off-highwayvehicles other than rail vehicles, or the like, joined together totravel along the route 102.

In one embodiment, tractive efforts (e.g., power output, horsepower,speed, and the like) and/or braking efforts of the vehicle system 100may be controlled to drive the vehicle system 100 along the route 102from an origin location to a destination location. The tractive and/orbraking efforts may be automatically controlled such that the tractiveand/or braking efforts provided by the vehicles 104, 106 withoutoperator intervention involved in changing these efforts. Alternativelyor additionally, the vehicle system 100 may provide prompts and noticesto an operator that direct the operator how to manually control theefforts of the vehicle system 100. For example, the system 100 mayprovide prompts to an operator to instruct the operator of whichoperational settings to use at a current time and/or which settings touse at upcoming times when the system 100 arrives at one or moreupcoming locations. The operational settings (e.g., settings thatcontrol tractive effort, braking effort, etc.) of thepropulsion-generating vehicles and/or non-propulsion-generating vehiclesmay be referred to herein as operational parameters.

The tractive efforts and braking efforts may be controlled bydesignating operational settings of the vehicle system 100 at one ormore locations along the route 102. By way of example, these operationalsettings can include power settings (e.g., throttle notch settings) thatcontrol the power output from the propulsion-generating vehicles 104 andbrake settings (e.g., dynamic brake settings) that control the brakingefforts of the propulsion-generating vehicles 104 and/or thenon-propulsion generating vehicles 106. The operational settings thatare designated for a trip of the vehicle system 100 from a firstlocation to a different, second location along the route 102 may bereferred to as a trip plan. The designated operational settings can beexpressed as a function of time elapsed during a trip along the route102 and/or distance along the route 102 in the trip plan.

The designated operational settings can be computed in order to improvehandling (e.g., control) of the vehicle system 100. For example, thedesignated operational settings can be determined in order to reduce thefrequency at which throttle notch settings and/or brake settings arechanged, to reduce abrupt jerking movements of the vehicle system 100 orsegments of the vehicle system 100, to reduce forces exerted on thecouplers 108, and the like.

In one embodiment, different propulsion-generating vehicles 104 may havedifferent operational settings at the same location and/or time alongthe route 102. For example, the propulsion-generating vehicles 104 maybe asynchronously controlled so that not all of the vehicles 104 in thevehicle system 100 and/or in a single consist 110, 112, 114 arecontrolled according to the same throttle and/or brake settings.Alternatively, the propulsion-generating vehicles 104 may be assignedinto different groups (e.g., the consists 110, 112, 114 or other groups)with virtual “fences” between the groups. A fence can demarcate a pairof groups of the propulsion-generating vehicles 104 on opposite sides ofthe fence. For example, if a fence is established between the consists112 and 114, then the propulsion-generating vehicles 104C-E in theconsist 112 may operate using a first designated throttle notch settingwhile the propulsion-generating vehicles 104F-G in the consist 114 mayoperate using a different, second designated throttle notch setting atthe same time. Operation of the vehicle system 100 that involves two ormore of the propulsion-generating vehicles 104 using differentoperational settings at the same time may be referred to as asynchronousdistributed power operation in one embodiment.

FIGS. 2 through 4 illustrate embodiments of how operations of thepropulsion-generating vehicles 104 in the vehicle system 100 can becontrolled in order to improve handling of the vehicle system 100 duringa trip while achieving one or more trip objectives and while remainingwithin operating constraints on the trip. A trip objective can be a goalthat the vehicle system 100 attempts to achieve by operating accordingto operational settings designated for the vehicle system 100. The tripobjectives may include a reduction in fuel consumption, emissiongeneration, and/or travel time relative to traveling with the samevehicle system 100 along the same route 102, but using differentoperational settings at one or more locations along the route 102.Another example of a trip objective can include fuel balancing, wherethe operational settings are determined in order to keep or maintain theamount of fuel stored onboard the different propulsion-generatingvehicles to be the same or within a designated amount (e.g., 1%, 3%, 5%,10%, or another value) over an entirety of the trip, over one or moresegments of the trip, or the like. For example, differentpropulsion-generating vehicles may consume fuel at different ratesand/or may have different amounts of fuel onboard prior to departure fora trip. The operational settings for the trip can be determined so thatthe different propulsion-generating vehicles carry the same or similaramounts of fuel. The operational settings can cause vehicles carryingmore fuel to consume more fuel than those vehicles carrying less fuel inorder to keep the distribution of fuel even across the vehicle system100. For example, the vehicles carrying less fuel than other vehiclesmay be restricted to a smaller range of throttle notch settings thanvehicles carrying more fuel. This can prevent the vehicles carrying lessfuel from consuming more fuel than the vehicles carrying more fuel. Overtime, the notch restrictions on the vehicles carrying less fuel cancause the balance of fuel carried by the vehicles in the vehicle systemto become more even (e.g., the amount of fuel carried by the vehicles iswithin a designated amount or range of each other).

Another example of a trip objective can be a number of nodes in thevehicle system 100. A node can represent a vehicle or coupler in thevehicle system 100 that is disposed between a coupler in tension and acoupler in compression. For example, if the coupler 108 between thevehicles 104E and 106D is in compression while the coupler 108 betweenthe vehicles 104C and 104D is in tension, then the coupler 108 betweenthe vehicles 104D and 104E may represent a node of the vehicle system100. A trip objective can be a reduction or elimination of nodes in thevehicle system 100 for an entire trip or one or more segments of thetrip, or keeping the number of nodes in the vehicle system below adesignated number. For example, if the number of nodes in the vehiclesystem 100 can be reduced by changing operational settings and/or fencepositions at one or more locations along a trip, then the operationalsettings and/or fence positions can be changed to reduce the number ofnodes.

The operating constraints may include speed limits (both lower limits onspeed and upper limits on speed), power requirements (e.g., minimumrequirements for power to propel the vehicle system 100 up an incline),time limitations on how long an operator may be working on the vehiclesystem 100, a system-wide schedule for the travel of multiple vehiclesystems on or across the route 102, or the like. Other examples ofoperating constraints can include fuel consumption limits, where certainoperational settings are not permitted for one or morepropulsion-generating vehicles as these settings could cause thevehicles to consume more fuel or to consume fuel at a greater rate thandesired. For example, a propulsion-generating vehicle may not bepermitted to be assigned a notch setting that would cause the vehicle toconsume more fuel than the vehicle is carrying and/or consume fuel atsuch a rate that the vehicle will not have sufficient fuel to complete atrip.

Another operating constraint can include engine derating. One or moreengines of the propulsion-generating vehicles may be derated and unableto generate the horsepower or tractive effort associated with the ratingof the engines. The decreased output or capability of these engines maybe used to limit what operational settings are assigned to differentvehicles to prevent the vehicles from having to operate the engines atlevels that exceed the derated capabilities of the engines. Thisderation may be due to an onboard failure or as the result of a desiredlimit (e.g., to maintain a desired train horsepower per ton).

Another example of an operating constraint can include a notch deltapenalty. Such a penalty can restrict how much and/or how quickly anoperational setting of a vehicle is allowed to change. For example, anotch delta penalty may not allow the throttle notch setting for apropulsion-generating vehicle to change by more than three positions(e.g., throttle notch one to throttle notch four). Instead, the vehiclemay be limited to changing throttle positions by three positions or lessat a time.

Another example of an operating constraint can be a limitation on howfrequently the group assignment is changed. For example, such aconstraint may not permit the group assignment of the vehicle system 100to change more frequently than a designated frequency or time period.

FIG. 2 is a flowchart of one embodiment of a method 200 for operatingthe vehicle system 100 shown in FIG. 1. The method 200 may be used inconjunction with the vehicle system 100. For example, the method 200 maybe used to create a trip plan for the vehicle system 100 that designatesoperational settings to be used to asynchronously control the operationsof the propulsion-generating vehicles 104 (shown in FIG. 1) during atrip along the route 102 (shown in FIG. 1) in order to improve handlingof the vehicle system 100. Additionally or alternatively, the method 200may be used to autonomously control the operations of thepropulsion-generating vehicles 104 in an asynchronous manner during atrip along the route 102 in order to improve handling of the vehiclesystem 100. Additionally or alternatively, the method 200 may be used todirect an operator to manually control the operations of thepropulsion-generating vehicles 104 in an asynchronous manner during atrip along the route 102 in order to improve handling of the vehiclesystem 100.

At 202, a synchronous trip plan for the trip is obtained. The trip planmay be synchronous in that the operational settings of thepropulsion-generating vehicles 104 that are designated by the trip planmay be the same for the propulsion-generating vehicles 104 at the samelocations. The trip plan may designate the operational settings of thevehicle system 100 in order to reduce fuel consumed, emissionsgenerated, and the like, by the vehicle system 100 relative to thevehicle system 100 traveling along the route 102 in the trip using oneor more different operational settings (e.g., according to manualcontrol and/or another, different trip plan). One or more examples oftrip plans (also referred to as mission plans or trip profiles) and howthe trip plans are determined are provided in U.S. patent applicationSer. No. 11/385,354 (referred to herein as the “'354 application”), theentire disclosure of which is incorporated by reference.

In one embodiment, the synchronous trip plan can be created at 202 bycollecting and using trip data, route data, and vehicle data. The tripdata includes information representative of one or more constraints ofthe trip, such as a starting location, an ending location, one or moreintermediate locations between the starting and ending locations, ascheduled time of arrival at one or more locations, weather conditions(e.g., direction and speed of wind) and the like. The route dataincludes information representative of the route 102, including grades,curvatures, speed limits, and the like. The vehicle data includesinformation representative of capabilities and/or limitations of thevehicle system 100, such as power outputs that can be provided by thevehicle system 100, tractive efforts provided by thepropulsion-generating vehicles 104 at different throttle notch settings,braking efforts provided by the vehicles 104, 106 at different brakenotch settings, and the like. The vehicle data also can include the size(e.g., mass, length, number of axles, weight distribution, or the like)of the vehicles 104 and/or 106 in the vehicle system 100. The trip plancan be computed from the beginning to the end of the trip and candesignate speeds of the vehicle system 100, synchronous notch settingsof the propulsion-generating vehicles 104, and synchronous brakesettings of the propulsion-generating vehicles 104, 106 at locationsalong the route 102.

At 204, handling parameters are calculated at one or more differentlocations along the route 102. The handling parameters may be calculatedprior to the vehicle system 100 embarking on the trip and/or duringtravel of the vehicle system 100 in the trip and prior to arriving atthe one or more different locations. The handling parameters areestimates or measurements of one or more aspects of the vehicle system100 and/or the route 102. Several examples of handling parameters aredescribed below. The handling parameters can be representative of forcesexerted on the couplers, energies stored in the couplers, relativevelocities of neighboring vehicles of the vehicles in the vehiclesystem, natural forces exerted on one or more segments of the vehiclesystem between two or more of the propulsion-generating vehicles,distances between neighboring vehicles in the vehicle system, momentumof one or more vehicles and/or one or more groups of the vehicles,virtual forces exerted on one or more of the vehicles, or the like. Themomentum may include changes in momentum, momentum transport, or thelike.

One example of handling parameters is coupler parameters. Couplerparameters include one or combinations of estimates, calculations,measurements, and/or simulations of coupler forces and/or energiesstored in the couplers 108 (shown in FIG. 1) of the vehicle system 100at one or more locations along the route 102 for the trip. In oneembodiment, the coupler forces and/or energies stored in the couplers108 can be estimated from a model of the couplers 108. For example, thecouplers 108 between the vehicles 104, 106 can be modeled as springshaving spring constants k and a damper (e.g., the mass of the vehicles104 and/or 106 to which the modeled spring is coupled). Due to thetractive efforts (e.g., power outputs) provided by thepropulsion-generating vehicles 104, the states of the vehicle system 100may undergo a transition and the forces exerted on the couplers 108and/or the energies stored in the couplers 108 that result from thistransition at different locations along the route 102 can be calculated(e.g., estimated or simulated) as a function of the tractive effortsprovided by the propulsion-generating vehicles 104 at the differentlocations.

By way of example only, a first coupler 108 may be expected to becomecompressed due to the expected deceleration of a first leadingpropulsion-generating vehicle 104 and the expected acceleration of afirst trailing propulsion-generating vehicle 104 that are caused bychanges in the grade of the route 102 during travel according to thesynchronous trip plan (e.g., when traversing a valley or low point inthe route 102). Another, second coupler 108 may be expected to becomestretched due to the expected acceleration of a second leadingpropulsion-generating vehicle 104 and the expected deceleration of asecond trailing propulsion-generating vehicle 104 that are caused bychanges in the grade of the route 102 during travel according to thesynchronous trip plan (e.g., when traversing a peak or high point in theroute 102). The first coupler 108 may be estimated to have a greatercompressive force than the second coupler 108 in this example.

One or more relationships between the coupler forces and/or energiesstored in the couplers 108 can be used to determine the couplerparameters. One example of a coupler parameter includes:

$\begin{matrix}{P_{c} = {\sum\limits_{j = 1}^{nc}f_{j}^{2}}} & \left( {{Equation}\mspace{14mu} {\# 1}} \right)\end{matrix}$

where P_(c) represents a coupler parameter, nc represents a number ofthe couplers 108 in the vehicle system 100 (e.g., the total number ofcouplers 108), and f represents the estimated or modeled coupler force.The coupler parameter (P_(c)) of Equation #1 may represent the sum ofsquares of all coupler forces between the first coupler 108 (e.g., whenj=1) and the n^(th) coupler 108 in the vehicle system 100. Anotherexample of a coupler parameter includes the maximum coupler force of thecouplers 108 at a location along the route 102.

Another example of a coupler parameter includes:

$\begin{matrix}{E = {\sum\limits_{j = 1}^{nc}{0.5\frac{f_{j}^{2}}{k_{j}}}}} & \left( {{Equation}\mspace{14mu} {\# 2}} \right)\end{matrix}$

where E represents another coupler parameter and k represents the springconstant of a modeled spring representative of the j^(th) coupler 108.The coupler parameter (E) of Equation #2 may represent the total energystored in the couplers 108 of j=1 through j=nc in the vehicle system 100at a location along the route 102. Additionally or alternatively, thecoupler parameter may include or represent an average of an absolutevalue of the coupler forces in the vehicle system 100. Additionally oralternatively, the coupler parameter may include or represent a sum,maximum, average, median, and the like of the absolute values of thecoupler forces in the vehicle system 100 that are at least as large as adesignated upper limit. The upper limit may be based on the location ofthe vehicle system 100 (e.g., the limit is based on the terrain beingtraveled over), vehicle data (e.g., the type of vehicles in the system100), coupler data (e.g., the type, health, age, and the like, of thecouplers in the system 100), and the like.

One or more of the coupler parameters described above and/or anothercoupler parameter that represents coupler force and/or energy stored inthe couplers 108 may be determined for the vehicle system 100 at one ormore locations along the route 102 during the trip. For example, priorto arriving at the locations, the coupler parameters may be calculatedor estimated for those locations using the trip data, the vehicle data,and/or the route data.

FIG. 3 illustrates coupler parameters 310 (e.g., coupler parameters310A-J) that are estimated for a vehicle system 300 to travel along aroute 302 in accordance with one example. The vehicle system 300 mayrepresent the vehicle system 100 (shown in FIG. 1) or a segment of thevehicle system 100. The vehicle system 300 includespropulsion-generating vehicles 304 (e.g., vehicles 304A-C), which canrepresent the propulsion-generating vehicles 104 (shown in FIG. 1) andnon-propulsion generating vehicles 306 (e.g., vehicles 306A-G), whichcan represent the non-propulsion generating vehicles 106 (shown in FIG.1). The vehicles 304, 306 are connected by couplers 108 (shown in FIG.1). The route 302 may represent a portion of the route 102 (shown inFIG. 1).

The coupler parameters 310 are shown alongside a horizontal axis 312that is representative of locations along the length of the vehiclesystem 300 and a vertical axis 314 that is representative of magnitudesof the coupler parameters 310. The size of the coupler parameters 310indicates the relative sizes of the coupler forces and/or storedenergies represented by the parameters 310. The coupler parameters 310represent the coupler forces and/or energies of the couplers 108 joinedto the respective vehicle 304, 306. For example, the coupler parameter310A represents the coupler forces and/or stored energies of the coupler108 connected to the vehicle 304A (or twice the coupler force and/orstored energy of the single coupler 108 connected to the vehicle 304A),the coupler parameter 310B represents the coupler forces and/or storedenergies of the couplers 108 connected to the opposite ends of thevehicle 304B, the coupler parameter 310C represents the coupler forcesand/or stored energies of the couplers 108 connected to the oppositeends of the vehicle 306A, and so on. Negative coupler parameters 310(e.g., the parameters 310A-B and 310G-J extending below the horizontalaxis 312) can represent couplers 108 undergoing compressive forces andpositive coupler parameters 310 (e.g., the parameters 310C-F extendingabove the horizontal axis 312) can represent couplers 108 undergoingtensile forces.

The coupler parameters 310 can be estimated for travel over the route302 prior to the vehicle system 300 actually traveling over the route302 and using the synchronous trip plan established for travel over theroute 302. The coupler parameters 310 may be calculated using one ormore of the relationships described above, or in another manner thatrepresents compression and/or tension in the couplers 108. In oneembodiment, relatively large variances in the coupler parameters 310 canindicate poor handling of the vehicle system 300. For example, a tripplan that causes a vehicle system 300 to have relatively large, positivecoupler parameters 310 and large, negative coupler parameters 310 mayindicate that traveling according to the trip plan will result in poorhandling of the vehicle system 300 relative to a trip plan that resultsin smaller positive coupler parameters 310 and/or smaller negativecoupler parameters 310.

Returning to the discussion of the method 200 shown in FIG. 2, anotherexample of handling parameters is terrain excitation parameters. Terrainexcitation parameters represent grades of the route 102 (shown inFIG. 1) at the different locations, masses of one or more of thevehicles 104, 106 (shown in FIG. 1) in the vehicle system 100 (shown inFIG. 1) at the different locations, and/or tractive efforts that are tobe provided by one or more of the propulsion-generating vehicles 104 atthe different locations according to a trip plan (e.g., a synchronoustrip plan).

A terrain index can represent the terrain under each vehicle 104, 106 asthe vehicle system 100 travels along the route 102. The terrain indexmay have a static component (e.g., a DC or average or steady component)and a dynamic component (e.g., an AC or varying or oscillatingcomponent). The static component of the terrain index can be defined as:

μ_(i) =−m _(i) g _(i) +T _(i)  (Equation #3)

where μ_(i) represents the static component of the terrain index beneaththe i^(th) vehicle 104, 106 in the vehicle system 100, m_(i) representsthe mass of the i^(th) vehicle 104, 106, g_(i) represents the grade ofthe route 102 beneath the i^(th) vehicle 104, 106, and T_(i) representsa designated tractive effort and/or braking effort to be provided by thei^(th) vehicle 104, 106 according to the trip plan (e.g., thesynchronous trip plan). In one aspect, a distribution of weight or massof the vehicles in the vehicle system may not be even. For example, themasses of the vehicles in one location or portion of the vehicle systemmay be larger than the masses of the vehicles in other locations orportions of the vehicle system. Alternatively, the masses of thevehicles may be even throughout the vehicle system, such as the massesof all vehicles 104, 106 being equal or within a designated range of oneanother, such as within 1%, 3%, 5%, 10%, or the like.

The dynamic component of the terrain index can be defined as:

$\begin{matrix}{{\overset{\sim}{\mu}}_{i} = {{{- m_{i}}g_{i}} + T_{i} - {\sum\limits_{j = 1}^{N}\mu_{i}}}} & \left( {{Equation}\mspace{14mu} {\# 4}} \right)\end{matrix}$

where {tilde over (μ)}_(i) represents the dynamic component of theterrain index and N represents the number of vehicles 104, 106 for whichthe terrain index is determined. In one embodiment, the couplerparameters 310 shown in FIG. 3 can represent the dynamic component ofthe terrain index for the vehicle system 300 instead of the couplerparameters of the vehicle system 300.

In one embodiment, the terrain excitation parameter may be based on thedynamic component of the terrain index. For example, the terrainexcitation parameter may be a filtered dynamic component of the terrainindex and represented by:

$\begin{matrix}{{e(k)} = {\sum\limits_{i = 1}^{k}{{\overset{\sim}{\mu}}_{i}a^{k - 1}}}} & \left( {{Equation}\mspace{14mu} {\# 5}} \right) \\{{e(i)} = {{\overset{\sim}{\mu}}_{i}a^{k - 1}}} & \left( {{Equation}\mspace{14mu} {\# 6}} \right)\end{matrix}$

where e(k) represents the terrain excitation parameter for the vehiclesystem 100 beneath the k^(th) vehicle 104, 106, a represents aconfigurable or tunable constant referred to as a spatial decay rate ofterrain input and having a value between 0 and 1, e(i) represents theterrain excitation parameter for the i^(th) vehicle 104, 106 in thevehicle system 100, and m represents the number of vehicles 104, 106 inthe vehicle system 100.

FIG. 4 illustrates terrain excitation parameters 410 that are estimatedfor the vehicle system 300 to travel along the route 302 in accordancewith one example. The terrain excitation parameters 410 are shownalongside a horizontal axis 412 representative of locations along thelength of the vehicle system 300 and a vertical axis 414 representativeof magnitudes of the terrain excitation parameters 310.

As shown in FIG. 4, when the trip plan directs the propulsion-generatingvehicles 304A-C to use the same braking efforts during traversal of thepeak or apex in the route 302, the terrain excitation parameters 410increase along the length of the vehicle system 300 and then decrease.For example, the terrain excitation parameters 410 corresponding tolocations below the back end of the vehicle system 300 to beneath thenon-propulsion generating vehicle 306C increase to a maximum, and thendecrease to a minimum beneath the propulsion-generating vehicle 306B,before increasing again beneath the propulsion-generating vehicle 306A.

The terrain excitation parameters 410 can be estimated for travel overthe route 302 prior to the vehicle system 300 actually traveling overthe route 302 and using the synchronous trip plan established for travelover the route 302. The terrain excitation parameters 410 may becalculated using one or more of the relationships described above, or inanother manner that represents compression and/or tension in thecouplers 108. In one embodiment, relatively large terrain excitationparameters 410 (e.g., large positive and/or large negative values) canindicate poor handling of the vehicle system 300. For example, a tripplan that causes a vehicle system 300 to have relatively large maximumor minimum terrain excitation parameters 410 may indicate that travelingaccording to the trip plan will result in poor handling of the vehiclesystem 300 relative to a trip plan that results in smaller maximum orminimum terrain excitation parameters 410.

Returning to the discussion of the method 200 shown in FIG. 2, anotherexample of handling parameters is node parameters. Node parametersrepresent a number of the nodes in the vehicle system 100 (shown inFIG. 1) and/or a rate of movement of the nodes in the vehicle system100. A node can represent a location in the vehicle system 100 where anabsolute value of force that is estimated to be exerted on a coupler 108is less than a designated threshold. In order to identify the presenceand locations of nodes, a rigid rope model of the vehicle system 100 maybe used. In such a model, the couplers 108 are treated as having noslack and the vehicle system 100 is treated as traveling according tothe trip plan (e.g., the synchronous trip plan). Locations where thecouplers 108 are estimated to have relatively large compressive forcesor relatively large tensile forces due to the tractive and/or brakingefforts designated by the trip plan and due to the grades in the route102 (shown in FIG. 1) are not identified as nodes. Other locations wherethe couplers 108 are estimated to have relatively small or nocompressive or tensile forces are identified as nodes.

With respect to the example shown in FIG. 3, the coupler parameter 310Gmay represent the location of a node in the vehicle system 300. Thenumber of nodes (e.g., one in the example of FIG. 3, but alternativelymay be a larger number) can be a node parameter. Additionally oralternatively, the rate of movement of the nodes in the vehicle systemcan be a node parameter. For example, as the vehicle system moves up anddown different grades of the route and/or using tractive and/or brakingefforts designated by the synchronous trip plan, the locations of thenodes within the vehicle system may change (e.g., move to anothercoupler 108). This movement can be estimated as a speed or rate ofmovement, such as in units of number of couplers per second, number ofvehicles per second, and the like.

Returning to the discussion of the method 200 shown in FIG. 2, anotherexample of handling parameters is neighboring velocity parameters. Theneighboring velocity parameters can represent differences in speedbetween neighboring vehicles 104 and/or 106 in the vehicle system 100shown in FIG. 1. For example, speeds of the vehicles 104, 106 travelingaccording to a synchronous trip plan can be estimated based on the sizes(e.g., masses) of the vehicles 104, 106, the location of the vehicles104, 106 in the vehicle system 100, the grade of the route 102, and thelike. Because the couplers 108 between the vehicles 104, 106 are notentirely rigid bodies, there may be some differences in the speeds ofthe vehicles 104, 106 that are directly connected with each other.

For example, a leading propulsion-generating vehicle 104 that isaccelerating according to a trip plan may at least temporarily travelfaster than another, heavier propulsion-generating vehicle 104 that isdirectly coupled to the leading propulsion-generating vehicle 104 and/orthan a non-propulsion generating vehicle 106 that is directly coupled tothe leading propulsion-generating vehicle 104. As another example, whencresting a hill, a first vehicle 104 or 106 that is on the downwardsloping side of the hill may be temporarily traveling faster than asecond vehicle 104 or 106 that is directly connected to the firstvehicle 104 or 106 and that is on the upward sloping side of the hill.In another example, when traversing a dip or low point in the route 102,a first vehicle 104 or 106 that is on the upward sloping side of the lowpoint may be temporarily traveling slower than a second vehicle 104 or106 that is directly connected to the first vehicle 104 or 106 and thatis on the downward sloping side of the low point. The differences inspeeds between the neighboring (e.g., adjacent) vehicles 104 and/or 106can vary forces exerted on the couplers 108 to generate jerkingmovements that decrease the handling of the vehicle system 100.

Node parameters represent a number of the nodes in the vehicle system100 (shown in FIG. 1) and/or a rate of movement of the nodes in thevehicle system 100. A node can represent a location in the vehiclesystem 100 where an absolute value of force that is estimated to beexerted on a coupler 108 is less than a designated threshold. In orderto identify the presence and locations of nodes, a rigid rope model ofthe vehicle system 100 may be used. In such a model, the couplers 108are treated as having no slack and the vehicle system 100 is treated astraveling according to the trip plan (e.g., the synchronous trip plan).Locations where the couplers 108 are estimated to have relatively largecompressive forces or relatively large tensile forces due to thetractive and/or braking efforts designated by the trip plan and due tothe grades in the route 102 (shown in FIG. 1) are not identified asnodes. Other locations where the couplers 108 are estimated to haverelatively small or no compressive or tensile forces are identified asnodes.

Another example of handling parameters is momentum. The momentum can bethe momentum of the vehicle system, one or more vehicles in the vehiclesystem, and/or one or more groups of vehicles in the vehicle system.Differences in momentum between different vehicles or groups of vehiclesin the vehicle system can indicate reduced handling parameters and/orincreased forces on couplers. For example, a larger momentum for a groupof vehicles that includes the vehicles 104A-E and 106A-C and a smallermomentum for a group of vehicles that includes the vehicles 104F-G and106D-I can indicate that the coupler 108 or couplers 108 between thesevehicle groups may be experiencing relatively large forces (e.g.,tensile forces) that result in reduced handling parameters of thevehicle system (e.g., relative to smaller momenta and/or smallerdifferences in momenta between the vehicle groups).

In one embodiment, the handling parameters may not be determined basedon a synchronous trip plan. A synchronous trip plan may not be obtainedat 202, but the handling parameters can be determined (e.g., estimated,calculated, or the like) based on one or more of the trip data, routedata, and/or vehicle data. For example, without having a previouslygenerated trip plan for an upcoming or current trip, one or more of thehandling parameters described herein may be determined using grades ofthe route, curvatures of the route, speed limits of the route, weight ofthe vehicle system, or the like.

At 206, total power outputs that are to be provided by the vehiclesystem 100 are determined at the locations along the route 102. Forexample, the total power outputs that are to be provided, in theaggregate, by the propulsion-generating vehicles 104 in the vehiclesystem 100 may be determined for at least some, or all, the samelocations at which the handling parameters are determined at 204.

In one embodiment, the total power outputs can be determined from thesynchronous trip plan. For example, the synchronous trip plan maydesignate the total power outputs to be provided by thepropulsion-generating vehicles 104 at the locations. Alternatively, thesynchronous trip plan can designate the individual power outputs to beprovided by each of the propulsion-generating vehicles 104 at thelocations, and the total power outputs of the vehicle system 100 can bedetermined from the sum or other aggregate of these individual poweroutputs. In another embodiment, the total power outputs can be derivedfrom other designated operational settings of the synchronous trip planat the locations. For example, the total power outputs may be calculatedfrom the designated speeds, accelerations, or other settings of thesynchronous trip plan at the locations. The total power outputs may bedetermined before, during, or after the handling parameters aredetermined. Optionally, the total power output can be determined withouta trip plan or synchronous trip plan. For example, based on the mass ofthe vehicle system, the locations of the propulsion-generating vehiclesin the vehicle system, and the grades of the route, an estimate orcalculation of the total power needed to propel the vehicle system alongthe route (e.g., to achieve the trip objective subject to operatingconstraints) may be made. Alternatively, an operator of the vehiclesystem 100 can designate or input the total power output. The operatorcan provide the total power output so that the method 600 can determinethe operational settings that result in providing the total power outputprovided by the operator.

At 208, asynchronous operational settings for the vehicle system 100 aredetermined. For example, the total power outputs can be divided amongthe propulsion-generating vehicles 104 in the vehicle system 100 at thelocations and based on the handling parameters by determining differentoperational settings for different vehicles 104, 106 at these locations.The total power outputs of the synchronous trip plan may be dividedamong the propulsion-generating vehicles 104 by designating the samethrottle and/or brake settings for each of the propulsion-generatingvehicles 104. Using the handling parameters that are determined at thelocations along the route 102, the same total power outputs at theselocations can be divided among the propulsion-generating vehicles 104 bydesignating different throttle and/or brake settings for thepropulsion-generating vehicles 104. For example, the synchronous tripplan may direct the seven propulsion-generating vehicles 104 to use thesame throttle setting to generate a total power output of 15,000horsepower at a location along the route 102. Optionally, the totalpower output may be determined without the aid of the synchronous tripplan, but may be determined using vehicle data, trip data, and/or routedata. The 15,000 horsepower output may be asynchronously divided amongthe propulsion-generating vehicles 104 by assigning different throttleand/or brake settings to the different propulsion-generating vehicles104. The propulsion-generating vehicles 104 may use the differentoperational settings in order to provide at least the 15,000 horsepower,but with improved handling of the vehicle system 100 relative to thesynchronous trip plan and/or relative to using other operationalsettings.

In one embodiment, the asynchronous operational settings are determinedbased on the handling parameters for all of the locations along theroute 102 for which the handling parameters were estimated.Alternatively, the asynchronous operational settings may be determinedfor a subset of these locations, such as for the locations associatedwith handling parameters that exceed one or more designated thresholds.The handling parameters that exceed the thresholds may indicatelocations or segments of the route 102 where handling of the vehiclesystem 100 may be more difficult than other locations or segments of theroute 102.

The different operational settings of the propulsion-generating vehicles104 may be designated for use by the vehicles 104 prior to embarking onthe trip. For example, before the vehicle system 100 begins the trip(e.g., leaves a location of trip origin), the method 200 may be used toconvert the same operational settings designated by the synchronous tripplan into the different (e.g., asynchronous) operational settings at oneor more locations along the route 102. Then, when the vehicle system 100arrives at or approaches the locations, the asynchronous operationalsettings may be used to control the propulsion-generating vehicles 104(e.g., autonomously or by directing an operator to manually implementthe asynchronous operational settings).

Alternatively, the method 200 may be used to convert the operationalsettings of the synchronous trip plan into the asynchronous operationalsettings in real time. By “real time,” it is meant that, in oneembodiment, the operational settings of the synchronous trip plan thatare associated with one or more locations along the route 102 (e.g., forimplementation by the propulsion-generating vehicles 104 at thoselocations) can be converted into the asynchronous operational settingsafter the vehicle system 100 has begun traveling on the route 102 forthe trip, but before or just as the vehicle system 100 arrives at theone or more locations. The vehicle system 100 may convert theoperational settings on an as-needed basis, such as by converting theoperational settings of the synchronous trip plan for a closer firstlocation, and then converting the operational settings of thesynchronous trip plan for a farther second location after passing thefirst location.

With respect to using the handling parameters to convert the operationalsettings of the synchronous trip plan into asynchronous operationalsettings, the method 200 may include (e.g., at 208) determiningdifferent operational settings for at least two or more of thepropulsion-generating vehicles 104 at a location along the route 102 inorder to change one or more of the handling parameters, such as to oneor more designated values or limits. For example, the method 200 mayinclude attempting to reduce or minimize one or more of the handlingparameters by changing the operational settings from the synchronoustrip plan. By “minimize,” it is meant that the value of one or more ofthe handling parameters is reduced relative to the handling parametersas determined (e.g., estimated or simulated) from the synchronous tripplan, but not necessarily reduced to the absolute lowest value possible.“Minimizing” also can mean reducing the value to at least a designatedlimit, but not necessarily the smallest possible value. By way ofexample only, minimizing the handling parameters can include reducingone or more coupler parameters, terrain excitation parameters, nodeparameters, and/or neighboring velocity parameters relative to thecorresponding coupler parameters, terrain excitation parameters, nodeparameters, and/or neighboring velocity parameters that are estimatedusing the synchronous trip plan, but not necessarily to a value of zero.

The designated limits to which the handling parameters are changed maybe based on vehicle data and/or route data. For example, the limits maybe expressed as a function of the terrain over which the vehicle systemtravels. As a result, the limits can be different at different locationsalong the route. As another example, the limits may be expressed as afunction of the vehicle size (e.g., weight, weight distribution, length,and the like), the type of vehicle (e.g., the power output capability ofthe system or vehicle 104), the type of coupler (e.g., the strength,age, and/or health of the couplers), and the like. Optionally, thedesignated limits may change value, such as to account for hysteresis orother impacts on the values of the handling parameters over time.

The handling parameters that are estimated or simulated using thesynchronous operational settings may be referred to as synchronoushandling parameters and the handling parameters that are estimated orsimulated using asynchronous operational settings may be referred to asasynchronous handling parameters. The handling parameters can be reducedby estimating or simulating the synchronous handling parameters,changing the synchronous operational settings to asynchronousoperational settings (while keeping the total power output of thevehicle system 100 at least as large as the total power output thatwould be obtained using the synchronous operational settings),estimating or simulating the asynchronous handling parameters, andcomparing the synchronous handling parameters with the asynchronoushandling parameters. Several iterations of this process may be performedso that several potential asynchronous handling parameters andassociated asynchronous operational settings are determined. Then, theasynchronous operational settings associated with one or moreasynchronous handling parameters that are reduced relative to thesynchronous handling parameters may be selected for use at theassociated location along the route 102. Additionally or alternatively,a history of handling parameters using synchronous and/or asynchronousoperational settings and handling parameters (e.g., as measured and/orestimated) from previous trips of the vehicle system 100 along the route102 may be used to determine the asynchronous operational settingsassociated with reduced handling parameters.

In one embodiment, the asynchronous operational settings are directlydetermined without using a synchronous trip plan (e.g., without usingthe synchronous operational settings or by basing the asynchronousoperational settings on previously generated synchronous operationalsettings). For example, instead of first obtaining or determining asynchronous trip plan and then determining the asynchronous operationalsettings from the synchronous trip plan, the asynchronous operationalsettings may be determined directly from data such as vehicle dataand/or route data. In one example, the asynchronous operational settingsmay be determined by determining one or more solutions to anoptimization problem represented by (and referred to as Equation #7):

${\min\limits_{{u_{1}{(x)}},\ldots \mspace{14mu},{u_{n}{(x)}}}{{\alpha (x)} \times {f\left( {u_{1},\ldots \mspace{14mu},u_{n}} \right)}}} + {{\beta (x)} \times {{fuel}\left( {u_{1},\ldots \mspace{14mu},u_{n}} \right)}} + {{\gamma (x)}{\sum\limits_{i = 1}^{n}\left( {u_{i} - u_{is}} \right)^{2}}}$

where u_(i)(x), . . . , u_(n)(x) represent tractive efforts (e.g., poweroutputs) of the propulsion-generating vehicles 104 numbered 1 through nin the vehicle system 100 that are to be determined by changing thesynchronous operational settings (where n represents the number ofvehicles 104 having operational settings that are to be modified). Forexample, u_(i)(x), . . . , u_(n)(x) may represent the variables in theabove Equation #7 that are to be solved for and used to determine theasynchronous operational settings. The variable u_(i)(x) represents thetractive effort provided by the i^(th) propulsion-generating vehicle 104in the vehicle system 100 at the location (x) using asynchronousoperational settings while the variable u_(is)(x) represents thetractive effort provided by the i^(h) propulsion-generating vehicle 104in the vehicle system 100 at the location (x) using synchronousoperational settings. When the tractive efforts u_(i)(x), . . . ,u_(n)(x) are determined, then the operational settings that areassociated with the tractive efforts u_(i)(x), . . . , u_(n)(x) may bedetermined (e.g., by identifying which throttle and/or brake settingsprovides the associated efforts u_(i)(x), . . . , u_(n)(x)). Optionally,the variables u_(i)(x), . . . , u_(n)(x) can include or represent thebraking efforts provided by the vehicles 104 and/or 106 of the vehiclesystem 100. The variable x represents a location or distance along theroute 102, and may change for different locations for which the tractiveefforts u_(i)(x), . . . , u_(n)(x) are being determined.

The function ƒ( ) can represent a function that captures (e.g.,mathematically represents) handling of the vehicle system 100, and isreferred to as a vehicle handling function. While the vehicle handlingfunction is shown in Equation #7 as being dependent on the tractiveefforts u_(i)(x), . . . , u_(n)(x) of the propulsion-generating vehicles104, the vehicle handling function may additionally or alternatively bedependent on one or more other factors, such as terrain (e.g., gradeand/or curvature of the route 102), a make-up of the vehicle system 100(e.g., the distribution of weight, propulsion-generating vehicles 104,and/or non-propulsion generating vehicles 106 in the vehicle system100), and/or speeds of the vehicle system 100 using the synchronousoperational settings.

The function fuel( ) can represent a function that captures (e.g.,mathematically represents) how much fuel is consumed by the vehiclesystem 100 (e.g., by the propulsion-generating vehicles 104) when thetractive efforts u₁(x), . . . , u_(n)(x) are generated by thepropulsion-generating vehicles 104 at the respective locations (x) alongthe route 102.

The variables α, β, and γ in Equation #7 can represent tuning parametersthat may be manually or autonomously changed in order to control therelative weights of different terms in the equation. The variable α(x)can represent a tuning parameter that is based on the total variation orother variation in the grade of the route 102 beneath the vehicle system100 at a location (x) along the route 102. For example, the variableα(x) can represent roughness of the route 102, which can be defined as:

$\begin{matrix}{{\alpha (x)} = {\sum\limits_{i = 1}^{n - 1}{{g_{i} - g_{i + 1}}}}} & \left( {{Equation}\mspace{14mu} {\# 8}} \right)\end{matrix}$

where g_(i) represents the grade of the route 102 underneath the i^(th)vehicle 104 or 106 at the location or distance (x). Optionally, thegrade can be scaled by mass of the vehicles 104, 106 in the aboveEquation #8. In one embodiment, one or more of the variables α, β, and γmay be based on vehicle data and/or route data. For example, α, β,and/or γ may be expressed as a function of the type of vehicles in thevehicle system, the age and/or health of the vehicles, the tractiveand/or braking output capabilities of the vehicles, the size of thevehicle system, and the like. As another example, α, β, and/or γ may beexpressed as a function of the location of the vehicle system and/or theterrain over which the vehicle system is currently located. As anotherexample, α, β, and/or γ may be expressed as a function of the type, age,and/or health of couplers in the vehicle system.

The variables α, β, and γ may have values that change in order to alterthe relative importance (e.g., weight) in the equation on handling ofthe vehicle system 100, fuel consumption of the vehicle system 100, andhow far or close the asynchronous operational settings should remain tothe synchronous operational settings (e.g., the degree of change in theoperational settings that is allowed to occur). In one example, thevalues of the variables α, β, and γ may be α(x)=1, β(x)=0, and γ(x)=0,which can result in only the handling performance of the vehicle system100 being improved, while the impact of changing the operationalsettings on fuel consumption and the difference between the synchronousand asynchronous operational settings are essentially ignored.

The values of the variables α, β, and γ may change based on distance (x)along the route 102. For example, if α(x) is represented by Equation #8,then the values of β(x) and γ(x) to be nonzero constants can cause moreemphasis to be placed on the vehicle handling function in Equation #7 inlocations where the terrain beneath the route 102 is relatively moredifficult (e.g., variations in the grade are more severe and/or morefrequent).

As described above, different values of tractive efforts u_(i)(x), . . ., u_(n)(x) may be inserted into Equation #7 in order to identifytractive efforts u_(i)(x), . . . , u_(n)(x) (e.g., and associatedasynchronous operational settings) that reduce one or more of thehandling parameters relative to the synchronous operational settings atone or more locations (x) along the route 102. In one embodiment, thepotential values of the tractive efforts u_(i)(x), . . . , u_(n)(x) maybe limited based on constraints, such as upper and lower magnitudelimits and rate bounds (e.g., limitations on how quickly the tractiveefforts can change with respect to distance).

Also as described above, because the variable u_(i)(x) represents thetractive effort provided by the i^(th) propulsion-generating vehicle 104in the vehicle system 100 at the location (x) using asynchronousoperational settings and the variable u_(is)(x) represents the tractiveeffort provided by the i^(th) propulsion-generating vehicle 104 in thevehicle system 100 at the location (x) using synchronous operationalsettings, then a constraint that may applied to Equation #7 may be thatthe values of u_(i)(x) may need to satisfy the following so that thetotal effort or total power output of the vehicle system 100 is notdecreased by changing from the synchronous operational settingsassociated with u_(is)(x) to the asynchronous operational settingsassociated with u_(i)(x):

$\begin{matrix}{{\sum\limits_{i = 1}^{n}{u_{i}(x)}} = {\sum\limits_{i = 1}^{n}{u_{is}(x)}}} & \left( {{Equation}\mspace{14mu} {\# 9}} \right)\end{matrix}$

The vehicle handling function ƒ( ) can be determined by attempting toreduce or minimize one or more of the handling parameters usingdifferent asynchronous operational settings (that result in differenttractive efforts u_(i)(x), . . . , u_(n)(x) being provided by thepropulsion-generating vehicles 104) at one or more locations along theroute 102. With respect to the coupler parameters, one or more functionsrepresentative of coupler forces or energy stored in the couplers 108may be used to reduce or minimize the coupler parameters. Thesefunctions may be applied to the couplers 108 over the entire vehiclesystem 100, within a segment of the vehicle system 100, and/or betweenthe first leading propulsion-generating vehicle 104A and the lasttrailing propulsion-generating vehicle 104G. By way of example only,these functions may include a sum of squares of the forces that areestimated to be exerted on the couplers 108, the maximum value of theforces exerted on the couplers 108 and/or energies stored in thecouplers 108, the minimum value of the forces exerted on the couplers108 and/or energies stored in the couplers 108, the maximum absolutevalue of the forces exerted on the couplers 108 and/or energies storedin the couplers 108, the sum of the forces exerted on the couplers 108and/or energies stored in the couplers 108, the absolute sum of theforces exerted on the couplers 108 and/or energies stored in thecouplers 108, and the like. Equations 1 and 2 above represent a coupleof examples of such functions.

With respect to the terrain excitation parameters, one or more functionsrepresentative of the terrain excitation parameters may be used toreduce or minimize the terrain excitation parameters. For example,different combinations of tractive efforts u_(i)(x), . . . , u_(n)(x)may be used in attempts to determine which combination results in afunction of the terrain excitation parameters being reduced orminimized. One example of such a function includes:

$\begin{matrix}{{f(\mu)} = {\sum\limits_{k = 1}^{N}{e(k)}^{2}}} & \left( {{Equation}\mspace{14mu} {\# 10}} \right)\end{matrix}$

where e(k)² represents the square of the terrain excitation parameterfor the k^(th) vehicle 104, 106 in the vehicle system 100 including Nvehicles 104, 106. The sum of the squares may be determined for theentire vehicle system 100, within a segment of the vehicle system 100,and/or between the first leading propulsion-generating vehicle 104A andthe last trailing propulsion-generating vehicle 104G.

Another example of a function of the terrain excitation parametersincludes:

$\begin{matrix}{{f(\mu)} = {k\overset{{ma}\; x}{{e(k)}}}} & \left( {{Equation}\mspace{14mu} {\# 11}} \right)\end{matrix}$

Such a function determines the maximum terrain excitation parameter andmay be used to identify the largest terrain excitation parameter in theentire vehicle system 100, within a segment of the vehicle system 100,and/or between the first leading propulsion-generating vehicle 104A andthe last trailing propulsion-generating vehicle 104G.

Another example of a function of the terrain excitation parametersincludes:

ƒ(μ)=Σ|e(k)|  (Equation #12)

Such a function determines the sum of the terrain excitation parametersand may be used to identify the sum of the terrain excitation parametersin the entire vehicle system 100, within a segment of the vehicle system100, and/or between the first leading propulsion-generating vehicle 104Aand the last trailing propulsion-generating vehicle 104G.

With respect to the node parameters, different combinations of tractiveefforts u_(i)(x), . . . , u_(n)(x) may be used in attempts to determinewhich combination results in the number of nodes being reduced orminimized and/or which combination results in the rate of movement ofone or more nodes being reduced or minimized.

With respect to the neighboring velocity parameters, one or morefunctions representative of the neighboring velocity parameters may beused to reduce or minimize the neighboring velocity parameters. Forexample, different combinations of tractive efforts u_(i)(x), . . . ,u_(n)(x) may be used in attempts to determine which combination resultsin a function of the neighboring velocity parameters being reduced orminimized. One example of such a function includes:

$\begin{matrix}{{f(v)} = {\sum\limits_{i = 1}^{N - 1}\left( {v_{i} - v_{i + 1}} \right)^{2}}} & \left( {{Equation}\mspace{14mu} {\# 13}} \right)\end{matrix}$

where v_(i) represents the velocity of the i^(th) vehicle 104 or 106 inthe vehicle system 100 having N vehicles 104, 106 and the term(v_(i)−v_(i+1)) represents the difference in velocities of neighboringvehicles 104 and/or 106.

Another example of a function of the neighboring velocity parametersincludes:

$\begin{matrix}{{f(v)} = \overset{{ma}\; x}{{v_{i} - v_{i + 1}}}} & \left( {{Equation}\mspace{14mu} {\# 14}} \right)\end{matrix}$

Such a function determines the maximum difference in velocities of theneighboring vehicles 104 and/or 106 and may be used to identify theneighboring velocity parameter in the entire vehicle system 100, withina segment of the vehicle system 100, and/or between the first leadingpropulsion-generating vehicle 104A and the last trailingpropulsion-generating vehicle 104G.

With respect to momentum being used as a handling parameter, thetractive efforts and/or braking efforts (e.g., operational settings) maybe determined for one or more locations along the route 102 may bedetermined in order to cause the vehicle system 100 and/or one or morevehicles 104, 106 to slow down (relative to a current or previous speed)so that the momentum of the vehicle system 100 and/or one or more groupsof vehicles 104, 106 to decrease (relative to a current or previousmomentum). For example, the operational settings may be determined tocause the momentum of one group of the vehicles 104, 106 to decrease toa designated momentum, such as the momentum of another group of thevehicles 104, 106 in the same vehicle system 100, to within a designatedrange of the momentum of the other group of the vehicles 104, 106 (e.g.,within 1%, 3%, 5%, 10%, or another range), or another value.Alternatively, the operational settings may be determined to cause themomentum of one group of the vehicles 104, 106 to increase to adesignated momentum, such as the momentum of another group of thevehicles 104, 106 in the same vehicle system 100, to within a designatedrange of the momentum of the other group of the vehicles 104, 106 (e.g.,within 1%, 3%, 5%, 10%, or another range), or another value. Designatingthe operational settings to cause the momentum of different vehicles104, 106 or vehicle groups in the same vehicle system 100 to be the sameor within a designated range of each other can reduce the forces exertedon couplers between the vehicles 104, 106 and/or vehicle groups and/orcan eliminate or reduce nodes in the vehicle system, and thereby improvehandling parameters of the vehicle system.

When the tractive efforts and/or braking efforts u_(i)(x), . . . ,u_(n)(x) are identified at one or more locations along the route 102that reduce the handling parameters relative to the synchronousoperational settings, the asynchronous operational settings thatcorrespond to the identified the tractive efforts and/or braking effortsu_(i)(x), . . . , u_(n)(x) are determined. For example, the throttlesettings and/or brake settings that are needed for each of thepropulsion-generating vehicles 104 to provide the identified tractiveefforts and/or braking efforts u_(i)(x), . . . , u_(n)(x) aredetermined, such as from a table, listing, previously determinedrelationship between the efforts and the settings, or the like. Flow ofthe method 200 then proceeds to 210.

At 210, a determination is made as to whether one or more of theasynchronous operational settings can be modified in order to achieve orimprove upon a trip objective. As described above, a trip objective caninclude a reduction in fuel consumption, emission generation, and/ortravel time. If one or more of the asynchronous operational settings canbe changed in order to reduce fuel consumption, emission generation,and/or travel time (relative to not changing the asynchronousoperational settings) while avoiding significant decreases in theimprovement in vehicle handling (that is achieved by using theasynchronous operational settings), then the asynchronous operationalsettings may be modified. On the other hand, if changing theasynchronous operational settings would not result in achieving orimproving upon a trip objective, then the asynchronous operationalsettings may not be changed.

FIG. 5 illustrates two relationships 500, 502 between differentasynchronous operational settings and a handling parameter at twodifferent locations along the route 102 (shown in FIG. 1) in accordancewith one example. The relationships 500, 502 may each represent how ahandling parameter (e.g., a coupler parameter representative of anamount of energy stored in one or more, or all, of the couplers 108 inthe vehicle system 100 shown in FIG. 1) varies at each the two differentlocations if the operational setting (e.g., a throttle setting for apropulsion-generating vehicle 104) is changed. The relationships 500,502 are shown alongside a horizontal axis 506 representative of theoperational parameter and a vertical axis 508 representative of thehandling parameter.

For example, the relationship 500 may represent how the handlingparameter is expected to change if the operational setting is changed ata first location along the route 102. As shown in FIG. 5, a previoussynchronous operational setting may be changed to an asynchronousoperational setting at a first value 510 to cause the handling parameterto be minimized or otherwise reduced to a lower value 512 at the firstlocation along the route 102. Changing the first value 510 of theasynchronous operational setting to a second value 514 may achieve orimprove upon a trip objective, such as by reducing the throttle settingin order to reduce the amount of fuel consumed by the vehicle system100. This change, however, also causes the handling parameter to beincreased from the lower value 512 to an upper value 516.

The determination of whether to decrease the operational setting to thevalue 514 may be based on one or more thresholds. For example, if thischange in operational setting results in a reduction in fuel consumptionand/or a reduction in the amount of emissions generated that is greaterthan one or more designated threshold amounts, and the change does notresult in the handling parameter increasing by more than a designatedthreshold amount from the lower value 512 to the upper value 516 and/orcause the vehicle system 100 to travel slower than a designated speed orproduce less than a designated total power output, then the change maybe implemented. If, however, the change results in a reduction in fuelconsumption and/or emissions generation that is smaller than a thresholdamount, the handling parameter increasing by more than a thresholdamount, and/or the vehicle system 100 to travel slower than a designatedspeed and/or produce less than a designated total power, then the changemay not be made to the previously identified asynchronous operationalsetting.

As another example, the relationship 502 may represent how the handlingparameter is expected to change if the operational setting is changed ata different, second location along the route 102. As shown in FIG. 5, aprevious synchronous operational setting may be changed to anasynchronous operational setting at a third value 518 to cause thehandling parameter to be minimized or otherwise reduced to a lower value520 at the second location along the route 102. As shown by therelationship 502, increasing or decreasing the operational setting willcause the handling parameter to increase. Increasing the operationalsetting may not be permitted as doing so may cause the vehicle system100 to consume excess fuel and/or generate increased emissions.Therefore, the operational setting may be decreased. In one embodiment,the operational setting may be decreased until the handling parameter isincreased by no more than a threshold amount or by no more than adesignated threshold value. For example, the operational setting may bedecreased until the lower value 520 of the handling parameter isincreased to an upper limit 522 on the handling parameter.

Returning to the description of the method 200 shown in FIG. 2, at 210,if the asynchronous operational setting can be modified at one or morelocations along the route 102 to achieve or improve upon a tripobjective, then flow of the method 200 may proceed to 212. Otherwise,the method 200 may proceed to 214.

At 212, the asynchronous operational settings are modified at one ormore locations along the route 102. For example, after determining theasynchronous operational settings and determining that the asynchronousoperational settings can be changed to achieve or improve upon a tripobjective, the asynchronous operational settings that can be changed aremodified. As a result, the modified asynchronous operational settingsthat are so determined can provide at least the total power output thatis dictated by the synchronous trip plan at various locations along theroute 102, but also improve upon the handling of the vehicle system 100relative to the synchronous trip plan and achieve one or more tripobjectives relative to the synchronous trip plan.

At 214, the asynchronous operational settings (e.g., the asynchronousoperational settings that were modified or that were not modified) areused to asynchronously control operations of the vehicle system 100. Forexample, the asynchronous operational settings can be used toautonomously control operations of the propulsion-generating vehicles104 along the route 102. Alternatively, the asynchronous operationalsettings can be used to direct an operator to manually controloperations of the propulsion-generating vehicles 104 along the route 102according to the asynchronous operational settings.

FIG. 6 is a flowchart of another embodiment of a method 600 foroperating the vehicle system 100 shown in FIG. 1. The method 600 may beused in conjunction with the vehicle system 100. For example, the method600 may be used to identify asynchronous operational settings for thevehicle system 100 when no synchronous trip plan is available or is notused to derive the asynchronous operational settings.

At 602, trip data representative of a trip to be traveled or currentlybeing traveled by the vehicle system 100, vehicle data representative ofthe vehicle system 100, and/or route data representative of the route102 of the trip are obtained. The data may be obtained from one or morememory devices disposed onboard and/or off-board of the vehicle system100, such as from a dispatch facility.

At 604, handling parameters are calculated at one or more differentlocations along the route 102 of the trip. For example, one or more ofthe handling parameters described above can be estimated from asimulation of travel of the vehicle system 100 and/or from previoustrips of the same or similar vehicle system 100 along the route 102. Inone embodiment, the terrain excitation parameter is estimated for travelof the vehicle system 100 over the route 102. If throttle and/or brakesettings are needed to determine the handling parameters, then defaultvalues, historical values (e.g., settings used during a previous tripover the route 102), and/or other values may be used to estimate thehandling parameters.

At 606, one or more locations of interest along the route 102 areidentified based on the handling parameters. A location of interest mayrepresent a section of the route 102 that may be relatively difficult orcomplex to control operations of the vehicle system 100 while providingimproved handling relative to one or more other sections of the route102. For example, a section of the route 102 having undulating terrainmay be more difficult or complex to control the vehicle system 100 overwith improved handling relative to the vehicle system 100 traveling overa relatively flat section of the route 102. In one embodiment, thelocations of interest are identified when the handling parameters thatare calculated at 604 exceed one or more designated thresholds. Forexample, the locations along the route 102 where the handling parametersare calculated to be relatively large may be identified as locations ofinterest.

At 608, a trip plan is created for the trip along the route 102. Forexample, a trip plan having synchronous operational settings for thepropulsion-generating vehicles 104 at various locations along the route102 may be created. As described above, in one embodiment, the trip planmay be created using one or more embodiments of the subject matterdescribed in the '354 application. The trip plan may be created usingthe trip data, vehicle data, and/or route data and may reduce fuelconsumed, emissions generated, and/or travel time for the trip relativeto the vehicle system 100 traveling along the route 102 for the tripaccording to another, different trip plan having different synchronousoperational settings.

In one embodiment, the trip plan may be created subject to one or moreconstraints placed on the operational settings used at the locations ofinterest. For example, a reduced speed limit (e.g., relative to agovernment or landowner-mandated speed limit) may be applied to thelocations of interest and/or a minimum speed limit that the vehiclesystem 100 is required to maintain may be applied to the locations ofinterest. Alternatively or additionally, limitations on how oftenthrottle and/or brake settings can be changed in the locations ofinterest can be placed on the trip plan. Other limitations on movementsand/or control of the vehicle system 100 may be applied as well. Thetrip plan may then be created so that the synchronous operationalsettings of the trip plan abide by these restrictions on the locationsof interest. For example, the trip plan may be created so that thevehicle system 100 is not directed to travel faster than upper speedlimits or slower than minimum speed limits at the associated locationsof interest. Other examples of constraints are described above, such asengine derating, notch delta penalties, limitations on how frequentlygroup assignments can change, limitations on nodes, etc.

At 610, total power outputs that are to be provided by the vehiclesystem 100 are determined at the locations along the route 102. Forexample, similar to 206 of the method 200 shown in FIG. 2, the totalpower outputs that are to be provided, in the aggregate, by thepropulsion-generating vehicles 104 in the vehicle system 100 may bedetermined for at least some, or all, the same locations at which thehandling parameters are determined at 204. Alternatively, an operator ofthe vehicle system 100 can designate or input the total power outputdirectly via throttle position. The operator can provide the total poweroutput so that the method 600 can determine the operational settingsthat result in providing the total power output provided by theoperator.

At 612, asynchronous operational settings for the vehicle system 100 aredetermined. For example, similar to 208 of the method 200, the totalpower outputs can be divided among the propulsion-generating vehicles104 in the vehicle system 100 at the locations and based on the handlingparameters by determining different operational settings for differentvehicles 104, 106 at these locations. The total power outputs of thesynchronous trip plan may be divided among the propulsion-generatingvehicles 104 by designating the same throttle and/or brake settings foreach of the propulsion-generating vehicles 104. Using the handlingparameters that are determined at the locations along the route 102, thesame total power outputs at these locations can be divided among thepropulsion-generating vehicles 104 by designating different throttleand/or brake settings for the propulsion-generating vehicles 104.

At 614, a determination is made as to whether one or more of theasynchronous operational settings can be modified in order to achieve orimprove upon a trip objective. For example, similar to 210 of the method200, if one or more of the asynchronous operational settings can bechanged in order to reduce fuel consumption, emission generation, and/ortravel time (relative to not changing the asynchronous operationalsettings) while avoiding significant decreases in the improvement invehicle handling (that is achieved by using the asynchronous operationalsettings), then the asynchronous operational settings may be modified.On the other hand, if changing the asynchronous operational settingswould not result in achieving or improving upon a trip objective, thenthe asynchronous operational settings may not be changed. If theasynchronous operational setting can be modified at one or morelocations along the route 102 to achieve or improve upon a tripobjective, then flow of the method 600 may proceed to 616. Otherwise,the method 600 may proceed to 614.

At 616, the asynchronous operational settings are modified at one ormore locations along the route 102. For example, similar to 212 of themethod 200, after determining the asynchronous operational settings anddetermining that the asynchronous operational settings can be changed toachieve or improve upon a trip objective, the asynchronous operationalsettings that can be changed are modified. As a result, the modifiedasynchronous operational settings that are so determined can provide atleast the total power output that is dictated by the synchronous tripplan at various locations along the route 102, but also improve upon thehandling of the vehicle system 100 relative to the synchronous trip planand achieve one or more trip objectives relative to the synchronous tripplan.

At 618, the asynchronous operational settings are used to asynchronouslycontrol operations of the vehicle system 100. For example, similar to214 of the method 200, the asynchronous operational settings can be usedto autonomously control operations of the propulsion-generating vehicles104 along the route 102. Alternatively, the asynchronous operationalsettings can be used to direct an operator to manually controloperations of the propulsion-generating vehicles 104 along the route 102according to the asynchronous operational settings.

In another embodiment, instead of determining the asynchronousoperational settings from a synchronous trip plan and/or determining theasynchronous operational settings at the locations associated withlarger handling parameters, a trip plan may be created in order to“optimize” (e.g., improve) the handling of the vehicle system 100 andone or more trip objectives. For example, a trip plan may be createdfrom the trip data, vehicle data, route data, and/or handlingparameters, with the trip plan decreasing the handling parameters atlocations along the route 102 while also reducing fuel efficiency,reducing the generation of emissions, and/or reducing travel time of thetrip, as described herein. For example, the trip plan may be created asingle time with the objectives of improving both handling and improvingone or more objectives of the trip.

FIG. 7 is a flowchart of another embodiment of a method 700 foroperating the vehicle system 100 shown in FIG. 1. The method 700 may beused in conjunction with the vehicle system 100. For example, the method700 may be used to identify asynchronous operational settings for thevehicle system 100 when no synchronous trip plan is available or is notused to derive the asynchronous operational settings.

At 702, trip data representative of a trip to be traveled or currentlybeing traveled by the vehicle system 100, vehicle data representative ofthe vehicle system 100, and/or route data representative of the route102 of the trip are obtained. The data may be obtained from one or morememory devices disposed onboard and/or off-board of the vehicle system100, such as from a dispatch facility. A trip plan formed fromsynchronous operational settings for the propulsion-generating vehicles104 may be created from the trip data, vehicle data, and/or route data,as described above, or received from an off-board source. Alternatively,the route data alone may be obtained at 702.

At 704, natural forces that are to be exerted on the vehicle system 100during travel along the route 102 during the trip are estimated. Thenatural forces exerted on the vehicle system 100 may be handlingparameters that are used to determine operational settings for thepropulsion-generating vehicles 104 and to improve the handling of thevehicle system 100. The natural forces include the forces exerted on thecouplers 108 (e.g., as predicted by a rigid rope model of the vehiclesystem 100 when only the gravitational forces on the vehicle system 100are considered). These estimated natural forces may be dependent on theterrain and may be independent of the propulsion-generating vehicles 104(e.g., independent of the tractive efforts generated by the vehicles104), drag forces, air-brake forces, and/or other operationalparameters. The natural forces may be estimated for one or more couplers108 disposed between propulsion-generating vehicles 104 in the vehiclesystem 100. In one embodiment, the natural forces are determined for asegment of the vehicle system 100 that includes one or morenon-propulsion generating vehicles 106 that are disposed between andthat interconnect two or more propulsion-generating vehicles 104.Alternatively or additionally, the natural forces may be determined forthe entire vehicle system 100 and/or for multiple segments of thevehicle system 100.

The natural forces exerted on couplers 108 may be estimated using routedata that is representative of the route 102 (e.g., curvature and/orgrade), and/or vehicle data that is representative of the size (e.g.,mass) of the vehicle system 100 and/or a segment of the vehicle system100:

F _(i−1) −F _(i) =m _(i) g _(i) +m _(i) {dot over (v)}  (Equation #15)

where F_(i) represents the natural force exerted on the i^(th) coupler108 in the vehicle system 100, F_(i−1) represents the natural forceexerted on the (i−1)^(th) coupler 108 in the vehicle system 100, m_(i)represents the mass of the i^(th) vehicle 104 or 106, g_(i) representsthe mean, average, or effective grade of the route 102 beneath thevehicle system 100, and {dot over (v)} represents the acceleration ofthe vehicle system 100. The acceleration ({dot over (v)}) may be theacceleration that is caused by gravitational force and can berepresented as:

$\begin{matrix}{\overset{.}{v} = \frac{\sum\limits_{i = 1}^{N}{m_{i}g_{i}}}{\sum\limits_{i = 1}^{N}m_{i}}} & \left( {{Equation}\mspace{14mu} {\# 16}} \right)\end{matrix}$

As a result, the natural force exerted on the i^(th) coupler 108 may bedefined as:

$\begin{matrix}{F_{i} = {{\sum\limits_{j = 1}^{i}{m_{j}g_{j}}} + {m_{j}\overset{.}{v}}}} & \left( {{Equation}\mspace{14mu} {\# 17}} \right)\end{matrix}$

If the natural force is positive at a coupler 108 (e.g., greater thanzero), the natural force can indicate that gravity tends to stretch thecoupler 108. Conversely, if the natural force is negative at the coupler108 (e.g., less than zero), the natural force can indicate that gravitytends to compress the coupler 108. The estimated natural forces can beused to determine a differential power (or effort) between thepropulsion-generating vehicles 104 on opposite sides of the coupler 108(but not necessarily directly connected to the coupler 108).

In one embodiment, the natural forces are used to determine a bunchingpower for the propulsion-generating vehicles 104 that are on oppositesides of the coupler 108. The bunching power can represent the totaldifferential power output with respect to a synchronous power outputthat is to be generated by these propulsion-generating vehicles 104. Forexample, the bunching power can represent a total difference between thepower output of the vehicles (as calculated using one or more methodsdescribed herein) and the power output of the vehicles if the vehicleswere using synchronous operational settings. As one example, thebunching power can be expressed as:

$\begin{matrix}{B = \left\{ \begin{matrix}{K\left( {p - n} \right)} & {{{if}\mspace{14mu} {{p - n}}} > t} \\0 & {otherwise}\end{matrix} \right.} & \left( {{Equation}\mspace{14mu} {\# 18}} \right)\end{matrix}$

where k represents a spring constant of the spring model of the coupler108, p represents a positive natural force (e.g., the maximum positivenatural force) exerted on the coupler 108, n represents an absolutevalue of a negative natural force (e.g., the maximum absolute negativenatural force) exerted on the coupler 108, B represents an estimatedbunching effort or power, and t represents a designated threshold.

As a result, if the positive natural force p is larger than thethreshold t plus the absolute negative natural force n, then theestimated bunching effort or power B is proportional to the differencebetween the positive natural force and the absolute value of thenegative natural force. If the absolute negative natural force n islarger than the threshold t plus the positive natural force p, then theestimated bunching effort or power B is proportional to the differencebetween the positive natural force and the absolute value of thenegative natural force. Otherwise, the estimated bunching effort orpower B is set to zero.

When the natural force on a coupler 108 is larger than the naturalcompressive force on the coupler 108, the bunching effort B is positive,which can indicate that the vehicle system 100 can be compressed tocompensate for the gravity stretching the vehicle system 100. Similarly,when the natural compressive force is larger than the natural stretchforce on the coupler 108, the bunching effort B is negative, which canindicate that the vehicle system 100 can be stretched to compensate forthe natural forces.

At 706, a determination is made as to whether the estimated naturalforce on one or more couplers 108 exceeds a designated threshold. Forexample, the natural force that is estimated to be exerted on a coupler108 at a location along the route 102 may be compared to a threshold. Ifthe natural force exceeds a designated threshold, then the natural forcemay be sufficiently large to warrant designating different operationalsettings (e.g., asynchronous operational settings) for thepropulsion-generating vehicles 104 disposed on opposite sides of thecoupler 108 in order to compensate for the natural force. Suchrelatively large natural forces may decrease handling of the vehiclesystem 100 and may be undesirable for the control of the vehicle system100. If the estimated natural force indicates that the coupler 108 mayexperience a relatively large tensile force at a location along theroute 102, then the operational settings of the propulsion-generatingvehicles 104 may be designated to compress the coupler 108.Alternatively, if the estimated natural force indicates that the coupler108 may experience a relatively large compressive force at a locationalong the route 102, then the operational settings of thepropulsion-generating vehicles 104 may be designated to stretch thecoupler 108. As a result, flow of the method 700 may proceed to 708.

On the other hand, if the estimated natural force does not exceed thethreshold, then the natural force may not be sufficiently large towarrant designating asynchronous operational settings for thepropulsion-generating vehicles 104 disposed on opposite sides of thecoupler 108 in order to compensate for the natural force. For example,if the estimated natural force indicates that the coupler 108 mayexperience a relatively small tensile or compressive force, then thenatural force may not significantly impact the handling of the vehiclesystem 100 in a negative or undesirable manner. As a result, flow of themethod 700 may proceed to 710.

At 708, asynchronous operational settings for the propulsion-generatingvehicles 104 disposed on opposite sides of the coupler 108 aredetermined. The asynchronous operational settings may be based on thebunching effort or horsepower. For example, the asynchronous operationalsettings may be determined so that the total (e.g., aggregate) poweroutput that is to be generated by the propulsion-generating vehicles 104on opposite sides of the coupler 108 is the bunching effort orhorsepower. The bunching effort or horsepower may be the effort (B)determined above using Equation #18 or another effort or horsepower thatreduces the estimated natural force on the coupler 108. The asynchronousoperational settings may be used to control operations of thepropulsion-generating vehicles 104, such as by automaticallyimplementing the asynchronous operational settings or by directing anoperator of the vehicle system 100 to manually implement theasynchronous operational settings at the location associated with theestimated natural force on the coupler 108.

At 710, the propulsion-generating vehicles 104 disposed on oppositesides of the coupler 108 for which the natural force is estimated arecontrolled using synchronous (e.g., the same) operational setting, suchas the same throttle settings. For example, because the estimatednatural force may be relatively small, the synchronous operationalsettings of a trip plan may be used for the propulsion-generatingvehicles 104 instead of changing the operational settings toasynchronous operational settings.

FIG. 8 is a schematic diagram of one embodiment of apropulsion-generating vehicle 800. The propulsion-generating vehicle 800may represent one or more of the propulsion-generating vehicles 104shown in FIG. 1. The propulsion-generating vehicle 800 includes apropulsion system 802, which can include one or more engines, motors,brakes, batteries, cooling systems (e.g., radiators, fans, etc.), andthe like, that operate to generate power output to propel the vehicle800. One or more input and/or output devices 804 (“Input/Output 804” inFIG. 8), such as keyboards, throttles, switches, buttons, pedals,microphones, speakers, displays, and the like, may be used by anoperator to provide input and/or monitor output of one or more systemsof the vehicle 800.

The propulsion-generating vehicle 800 includes an onboard control system806 that controls operations of the propulsion-generating vehicle 800.For example, the control system 806 may determine the asynchronousoperational settings for the vehicle 800 and at least one otherpropulsion-generating vehicle in the same vehicle system. Alternatively,the control system 806 may entirely or partially be disposed off-boardthe vehicle 800, such as at a dispatch facility or other facility. Thevehicle system 100 (shown in FIG. 1) that may include thepropulsion-generating vehicle 800 may include only a single vehicle 800having the control system 806 that receives or determines theasynchronous operational settings described herein. Alternatively, thevehicle system 100 may have multiple vehicles 800 with the controlsystems 806 that receive or determine the asynchronous operationalsettings.

Other propulsion-generating vehicles in the vehicle system 100 may becontrolled based on the asynchronous operational settings that arecommunicated from the propulsion-generating vehicle 800 that has thecontrol system 806 in order to control the operations of the otherpropulsion-generating vehicles. Alternatively, severalpropulsion-generating vehicles 800 in the vehicle system 100 may includethe control systems 806 and assigned priorities among the controlsystems 806 may be used to determine which control system 806 controlsoperations of the propulsion-generating vehicles 800.

The control system 806 is communicatively coupled with a communicationunit 808. The communication unit 808 communicates with one or moreoff-board locations, such as another vehicle (e.g., anotherpropulsion-generating vehicle in the same vehicle system 100, a dispatchfacility, another vehicle system, or the like). The communication unit808 can communicate via wired and/or wireless connections (e.g., viaradio frequency). The communication unit 808 can include a wirelessantenna 810 and associated circuitry and software to communicatewirelessly. Additionally or alternatively, the communication unit 808may be connected with a wired connection 812, such as one or more buses,cables, and the like, that connect the communication unit 808 withanother vehicle in the vehicle system or consist (e.g., a trainline,multiple unit cable, electronically controlled pneumatic brake line, orthe like). The communication unit 808 can be used to communicate (e.g.,transmit and/or receive) a variety of information described herein. Forexample, the communication unit 808 can receive the trip plan havingsynchronous operational settings, trip data, route data, vehicle data,operational settings from another propulsion-generating vehicle 800and/or another control unit 806, and/or other information that is usedto determine the handling parameters and asynchronous operationalsettings described herein. The communication unit 808 can transmitasynchronous operational settings, such as the asynchronous operationalsettings determined by the control system 806 and/or received from anoff-board source, to one or more other propulsion-generating vehicles inthe vehicle system 100. These transmitted asynchronous operationalsettings are used to direct the operations of the otherpropulsion-generating vehicles.

The control system 806 includes units that perform various operations.The control system 806 and one or more of the units may represent ahardware and/or software system that operates to perform one or morefunctions described herein. For example, the control system 806 and/orthe illustrated units may include one or more computer processor(s),controller(s), or other logic-based device(s) that perform operationsbased on instructions stored on a tangible and non-transitory computerreadable storage medium. Alternatively, the control system 806 and/orthe units may include one or more hard-wired devices that performoperations based on hard-wired logic of the devices. The control system806 and/or the units shown in FIG. 8 may represent the hardware thatoperates based on software or hardwired instructions, the software thatdirects hardware to perform the operations, or a combination thereof.

In the illustrated embodiment, the control system 806 includes an energymanagement unit 814 that receives input to create a trip plan. Forexample, the energy management unit 814 may receive trip data, vehicledata, and/or route data in order to create a trip plan havingsynchronous operational settings. As described above, such a trip planmay be used to determine asynchronous operational settings to improvethe handling of the vehicle system 100 and/or to identify locations ofinterest along the route 102 where the asynchronous operational settingsare to be determined in order to improve handling. Additionally oralternatively, the energy management unit 814 may create the trip planwith asynchronous operational settings, and may do so by attempting toreduce one or more of the handling parameters while also reducing thefuel consumed by the vehicle system 100, the emissions generated by thevehicle system 100, and/or the travel time to complete the trip. Forexample, the energy management unit 814 may determine the asynchronousoperational settings for the propulsion-generating vehicles 104, 800 ofthe vehicle system 100 at one or more locations along the route 102 inorder to reduce the handling parameters, fuel consumed, emissionsgenerated, and/or travel time relative to another trip plan for the sametrip and same vehicle system 100 that includes synchronous operationalsettings at one or more of the locations. Optionally, the energymanagement unit 814 that determines the synchronous and/or asynchronoustrip plan may be disposed off-board of the vehicle 800 and maycommunicate the trip plan to the control system 806.

An effort determination unit 816 examines the trip plan to determine thetotal power output demanded from the propulsion-generating vehicles 104,800 in the vehicle system 100 by the trip plan at one or more locationsalong the route 102. For example, the effort determination unit 816 canidentify the estimated or anticipated power outputs of each of thepropulsion-generating vehicles based on the designated operationalsettings (e.g., throttle notch positions) in the trip plan and then sumthese power outputs to determine the total power output to be providedby the vehicle system 100.

A handling unit 818 calculates one or more handling parameters describedabove. The handling unit 818 can estimate the values of the handlingparameters at one or more locations along the route 102, as describedabove. The handling unit 818 can determine these handling parametersusing the operational settings designated by the trip plan, also asdescribed above.

A post processing unit 820 determines the asynchronous operationalsettings for two or more of the propulsion-generating vehicles in thevehicle system. For example, the post processing unit 820 can examinethe total power outputs derived from the trip plan by the effortdetermination unit 816 and the handling parameters estimated by thehandling unit 818. The post processing unit 820 may then determineasynchronous operational settings that improve handling of the vehiclesystem 100 (e.g., by reducing one or more of the handling parameters)while providing the total power outputs of the vehicle system 100, asdescribed above. The post processing unit 820 may optionally determineif the asynchronous operational settings can be modified to achieve orimprove upon one or more trip objectives, such as fuel consumption,travel time, emissions generation, and the like.

A controller unit 822 forms instructions that are based on theasynchronous operational settings to control movement of thepropulsion-generating vehicle 800 and/or one or more otherpropulsion-generating vehicles in the vehicle system 100. For example,the controller unit 822 can create one or more data signals or packetsthat represent the asynchronous operational settings determined by thepost processing unit 820. These instructions may be communicated to thepropulsion system 802 of the vehicle 800 and/or to similar propulsionsystems of other propulsion-generating vehicles in the same vehiclesystem 100 to autonomously control movements of thepropulsion-generating vehicles. The propulsion systems that receive theinstructions may automatically implement the throttle and/or brakesettings dictated by the asynchronous operational settings. Optionally,the instructions may be communicated to the one or more output devices804 of the vehicle 800 and/or one or more similar output devices onother propulsion-generating vehicles in the vehicle system 100 to directone or more operators on how to manually change throttle and/or brakesettings of the propulsion-generating vehicles according to theasynchronous operational settings.

In one embodiment, the controller unit 822 may determine the actualspeed of the propulsion-generating vehicle 800 and/or one or more otherpropulsion-generating vehicles in the vehicle system 100. For example,the controller unit 822 may receive or measure data from the propulsionsystem 802 that represents the actual speed of the propulsion-generatingvehicle 800. This data may be obtained from a speed sensor that isincluded in the propulsion system 802. Additionally or alternatively,the controller unit 822 may receive similar data from otherpropulsion-generating vehicles in the vehicle system 100.

The controller unit 822 can compare the actual speed of thepropulsion-generating vehicle 800, the other propulsion-generatingvehicles, and/or the vehicle system 100 (e.g., which may be representedby the actual speeds of one or more of the propulsion-generatingvehicles) to a speed that is designated by a trip plan (e.g., asynchronous or asynchronous trip plan). If the actual speed differs fromthe designated speed, the controller unit 822 may identify a change inthrottle settings and/or brake settings for one or more of thepropulsion-generating vehicles in the vehicle system 100 that can beused to reduce or eliminate the difference between the actual anddesignated speeds. The controller unit 822 may direct (e.g., bytransmitting instructions) to one or more of the propulsion-generatingvehicles to change the respective throttle settings and/or brakesettings to reduce or eliminate the difference between the actual anddesignated speeds. The controller unit 822 may also determine acorresponding change in the throttle settings and/or brake settings ofone or more other propulsion-generating vehicles in order to maintainimproved handling of the vehicle system 100. For example, if a groupbunching effort is being maintained between two or morepropulsion-generating vehicles or consists of propulsion-generatingvehicles, then a change in the throttle settings of one vehicle orconsist to cause the actual speed to match the designated speed mayrequire a change in the throttle settings of another vehicle or consistin order to maintain the group bunching effort. The controller unit 822can identify this change in the settings of the other vehicle or consistand communicate the change to the other vehicle or consist forimplementation.

Although connections between the components in FIG. 8 are not shown, twoor more (or all) of the illustrated components may be connected by oneor more wired and/or wireless connections, such as cables, busses,wires, wireless networks, and the like.

In one embodiment, a method (e.g., for determining operational settingsfor a vehicle system having multiple vehicles connected with each otherby couplers to travel along a route) includes identifying total poweroutputs to be provided by propulsion-generating vehicles of the vehiclesin the vehicle system. The total power outputs are determined fordifferent locations of the vehicle system along the route. The methodalso includes calculating handling parameters of the vehicle system atone or more of the different locations along the route. The handlingparameters are representative of at least one of forces exerted thecouplers, energies stored in the couplers, relative velocities ofneighboring vehicles of the vehicles in the vehicle system, or naturalforces exerted on one or more segments of the vehicle system between twoor more of the propulsion-generating vehicles. The method also includesdetermining asynchronous operational settings for thepropulsion-generating vehicles at the different locations along theroute. The asynchronous operational settings represent differentoperational settings for the propulsion-generating vehicles that causethe propulsion-generating vehicles to provide at least the total poweroutputs at the respective different locations while changing thehandling parameters of the vehicle system to one or more designatedvalues at the different locations along the route. The method furtherincludes communicating the asynchronous operational settings to thepropulsion-generating vehicles in order to cause thepropulsion-generating vehicles to implement the asynchronous operationalsettings at the different locations.

In another aspect, the asynchronous operational settings are determinedby identifying the different operational settings for thepropulsion-generating vehicles that reduce the handling parametersrelative to different handling parameters associated with usingsynchronous operational settings for the propulsion-generating vehiclesat the respective different locations to provide the total power outputsat the respective different locations.

In another aspect, the handling parameters include coupler parametersrepresentative of at least one of the forces exerted on the couplers orthe energies stored in the couplers.

In another aspect, the handling parameters include terrain excitationparameters representative of at least one of grades of the route at therespective different locations, masses of one or more of the vehicles inthe vehicle system at the respective different locations, or tractiveefforts provided by one or more of the propulsion-generating vehicles atthe respective different locations.

In another aspect, identifying one or more nodes in the vehicle system,the one or more nodes representative of an estimated force exerted on acoupler that has an absolute value that is less than a designatedthreshold. The handling parameters include node parametersrepresentative of at least one of a number of the nodes in the vehiclesystem or a rate of movement of the nodes in the vehicle system.

In another aspect, the handling parameters include neighboring velocityparameters representative of the relative velocities of neighboringvehicles of the vehicles in the vehicle system and determined byidentifying estimated differences in estimated speed between theneighboring vehicles in the vehicle system.

In another aspect, the method includes modifying the asynchronousoperational settings to reduce at least one of an amount of fuel to beconsumed by the vehicle system, an amount of emissions to be generatedby the vehicle system, or a travel time of the vehicle system for thetrip while maintaining a resulting increase in the handling parametersbelow a designated threshold.

In another aspect, the handling parameters include the natural forcesthat are representative of one or more tensile or compressive forcesexerted on the one or more segments of the vehicle system from agravitational force.

In another aspect, the total power outputs to be provided bypropulsion-generating vehicles are identified from a synchronous tripplan that designates synchronous operational settings for thepropulsion-generating vehicles at the locations. When the vehicle systemtravels along the route according to the synchronous trip plan causesthe vehicle system to reduce at least one of fuel consumed, emissionsgenerated, or travel time relative to another, different trip plan thatdesignates one or more other, different synchronous operationalsettings.

In another aspect, the method also includes at least one of autonomouslyimplementing the asynchronous operational settings at the differentlocations or communicating the asynchronous operational settings for thevehicle system at one or more of a current location or an upcominglocation to an operator of the vehicle system for the operator tomanually implement the asynchronous operational settings.

In another aspect, the method also includes modifying the one or moredesignated values to which the handling parameters are changed based onat least one of a terrain of the route, a mass distribution of thevehicle system, a type of the vehicle system, or a type of the couplersin the vehicle system.

In one embodiment, a system (e.g., a control system for a vehiclesystem) includes an effort determination unit configured to identifytotal power outputs to be provided by a vehicle system that includesmultiple vehicles connected with each other by couplers to travel alonga route. The effort determination unit also is configured to identifythe total power outputs to be provided by propulsion-generating vehiclesof the vehicles in the vehicle system at different locations of thevehicle system along the route. The system includes a handling unitconfigured to calculate handling parameters of the vehicle system at oneor more of the different locations along the route. The handlingparameters are representative of at least one of forces exerted thecouplers, energies stored in the couplers, relative velocities ofneighboring vehicles of the vehicles in the vehicle system, or naturalforces exerted on one or more segments of the vehicle system between twoor more of the propulsion-generating vehicles. The system includes aprocessing unit configured to determine asynchronous operationalsettings for the propulsion-generating vehicles at the differentlocations along the route. The asynchronous operational settingsrepresent different operational settings for the propulsion-generatingvehicles that cause the propulsion-generating vehicles to provide atleast the total power outputs at the respective different locationswhile changing the handling parameters of the vehicle system to one ormore designated values at the different locations along the route. Theasynchronous operational settings are configured to be communicated tothe propulsion-generating vehicles in order to cause thepropulsion-generating vehicles to implement the asynchronous operationalsettings at the different locations.

In another aspect, the processing unit is configured to identify thedifferent operational settings for the propulsion-generating vehiclesthat reduce the handling parameters relative to different handlingparameters associated with using synchronous operational settings forthe propulsion-generating vehicles at the respective different locationsto provide the total power outputs at the respective differentlocations.

In another aspect, the handling parameters include coupler parametersrepresentative of at least one of the forces exerted on the couplers orthe energies stored in the couplers.

In another aspect, the handling parameters include terrain excitationparameters based on at least one of grades of the route at therespective different locations, masses of one or more of the vehicles inthe vehicle system at the respective different locations, or tractiveefforts provided by one or more of the propulsion-generating vehicles atthe respective different locations.

In another aspect, the handling unit is configured to identify one ormore nodes in the vehicle system. The one or more nodes arerepresentative of an estimated force exerted on a coupler that has anabsolute value that is less than a designated threshold. The handlingparameters include node parameters representative of at least one of anumber of the nodes in the vehicle system or a rate of movement of thenodes in the vehicle system.

In another aspect, the handling parameters include neighboring velocityparameters representative of the relative velocities of neighboringvehicles of the vehicles in the vehicle system and determined byidentifying estimated differences in estimated speed between theneighboring vehicles in the vehicle system.

In another aspect, the processing unit is configured to modify theasynchronous operational settings to reduce at least one of an amount offuel to be consumed by the vehicle system, an amount of emissions to begenerated by the vehicle system, or a travel time of the vehicle systemfor the trip while maintaining a resulting increase in the handlingparameters below a designated threshold.

In one embodiment, a method (e.g., for determining operational settingsfor a vehicle system having two or more propulsion-generating vehiclescoupled with each other by one or more non-propulsion generatingvehicles) includes obtaining route data and vehicle data. The route datais representative of one or more grades of a route at one or morelocations along the route that is to be traveled by the vehicle system.The vehicle data is representative of a size of the one or morenon-propulsion generating vehicles disposed between thepropulsion-generating vehicles. The method also includes calculating oneor more estimated natural forces that are to be exerted on couplersconnected with the one or more non-propulsion generating vehicles of thevehicle system at the one or more locations along the route. The one ormore estimated natural forces are based on the size of the one or morenon-propulsion generating vehicles and the one or more grades of theroute at the one or more locations along the route. The method alsoincludes determining asynchronous operational settings to be implementedby the two or more propulsion-generating vehicles at the one or morelocations along the route. Implementing the asynchronous operationalsettings by the two or more propulsion-generating vehicles reduces oneor more actual natural forces that are actually exerted on the couplersto forces that are smaller than the one or more estimated natural forceswhen the vehicle system travels over the one or more locations along theroute.

In another aspect, when the one or more estimated natural forces aretensile forces, the asynchronous operational settings instruct the twoor more propulsion-generating vehicles to implement at least one ofdifferent throttle settings or different brake settings to compress thecouplers connected with the non-propulsion generating vehicles.

In another aspect, when the one or more estimated natural forces arecompressive forces, the asynchronous operational settings instruct thetwo or more propulsion-generating vehicles to implement at least one ofdifferent throttle settings or different brake settings to stretch thecouplers connected with the non-propulsion generating vehicles.

In one embodiment, a method (e.g., for determining operational settingsof a vehicle system) includes obtaining route data and vehicle data. Theroute data is representative of one or more grades of a route at one ormore locations along the route that is to be traveled by a vehiclesystem having two or more propulsion-generating vehicles coupled witheach other by one or more non-propulsion generating vehicles. Thevehicle data is representative of a size of the one or morenon-propulsion generating vehicles disposed between thepropulsion-generating vehicles. The method also includes calculatinghandling parameters of the vehicle system at one or more differentlocations along the route based on the route data and the vehicle data.The handling parameters are representative of at least one of forcesexpected to be exerted the couplers, energies expected to be stored inthe couplers, expected relative velocities of neighboring vehicles ofthe vehicles in the vehicle system, or expected natural forces exertedon one or more segments of the vehicle system between two or more of thepropulsion-generating vehicles. The method further includes determiningasynchronous operational settings to be implemented by the two or morepropulsion-generating vehicles at the one or more locations along theroute based on the handling parameters. The asynchronous operationalsettings are determined by identifying a combination of the asynchronousoperational settings at the different locations along the route thatresult in the handling parameters being decreased to one or moredesignated limits.

Additional inventive subject matter described herein relates to ways ofdetermining the asynchronous operational settings described above for acurrent or upcoming trip of a vehicle system. Specifically, methods ofcomputing power and/or brake settings (also called notches) topropulsion-generating vehicles in the vehicle system in order to obtainimproved train handling (relative to operating the vehicle system inanother manner) are disclosed. In one aspect, the vehicle system isoperated as a distributed power (DP) vehicle system. The vehicle systemincludes propulsion-generating vehicles placed at different locations inthe vehicle system, and operating these propulsion-generating vehiclesusing different operational settings (e.g., different notches) at thesame time. As described above, the propulsion-generating vehicles can bedivided into groups in the vehicle system. In one example, these groupsmay be identified by placing one or more virtual “fences” between thedifferent groups of propulsion-generating vehicles. A fence can be usedto demarcate different groups of propulsion-generating vehicles, whichcan be referred to as consists. The propulsion-generating vehicles inthe different groups are allowed (but not required) to have differentoperational settings (e.g., notches). For example, the vehicles in thesame group can have the same operational setting, or notch, at a giventime.

In one embodiment, the system and method described herein uses modelpredictive control (MPC) to determine the time and/or location along aroute being traveled by the vehicle system to change which vehicles areincluded in the different groups to improve handling parameters of thevehicle system while satisfying other constraints (e.g., limitations onthe frequency of changes in which vehicles are in which groups, bunchinghorsepower at the time of movement, and the like). MPC can includecalculating or estimating handling parameters for the vehicle system atdifferent locations and/or times along a route for an upcoming portionof a trip. These handling parameters may be calculated or estimatedmultiple times for the same location of the vehicle system and/or timealong the trip, with different handling parameters calculated fordifferent vehicle groups and/or fence positions. The handling parametersare predicted for an upcoming trip (e.g., prior to the vehicle systembeginning to move for the trip) and/or for an upcoming segment of thetrip (e.g., while the vehicle system is moving during the trip).Different sequences of changes to the vehicle groups and/or fencepositions may be examined and compared with each other to identify thesequence or sequences that improve (e.g., increase or reduce, asappropriate) the handling parameters the most, more than one or moreother sequences (but not necessarily all other sequences), or by atleast a designated threshold amount.

In another embodiment, the times and/or locations where changes in whichvehicles are included in which groups (also referred to as movementpoints or change points) can be found by examining an entire plannedtrip of the vehicle system. Alternatively, other techniques can be used.

In another embodiment, the movement points or change points aredetermined by using a “categorize and merge” technique. In thistechnique, each movement point is categorized as either TBD (e.g., thefence position can be in any location in the vehicle system or thevehicles may be in any group) or a selected position (e.g., a specificfence position in the vehicle system or the vehicles are in specificgroups). The category TBD is selected when the group assignments of thevehicles do not differ significantly from each other in benefit.Otherwise, the group assignments of the vehicles with the mostsignificant benefit, or that has a more significant benefit than one ormore other groups of the vehicles, is selected. Then, an iterativesearching technique is used to merge or split TBD segments into selectedgroup assignments of the vehicles to satisfy the constraints. As usedherein, the term “group assignments” refers to a state of the vehicles,such as an identification of which vehicles are included in which groupsat a given or selected time.

The subject matter described herein solves a problem of ensuringimproved automatic handling of the vehicle system in several manners,including by making use of asynchronous distributed power operation(e.g., by allowing different propulsion-generating vehicles in a vehiclesystem to have different power settings). Additionally, the subjectmatter changes which vehicles are included in which groups within thevehicle system to further improve train handling. The change in whichvehicles are included in which groups can be performed by movinglocations of the virtual fences. While some vehicle systems have beenusing empirical “rules of thumb” and heuristics to control vehiclesystems and keep the vehicle systems bunched so that slack action in thevehicle system does not run out, these rules usually lack physical ormathematical justification. Moreover, these rules rapidly becomecomplicated to use for a human operator (even more so if the number ofgroups or fences increases), who must control speed, brakes, and othervariables in addition to modulating multiple notches to obtainacceptable handling of the vehicle system. Additionally, it can bedifficult for an operator to determine deviations from a synchronousplan, based on the distribution of weight in the vehicle system, terrainproperties, and speed.

FIG. 9 is a schematic illustration of another embodiment of a vehiclesystem 900. The vehicle system 900 includes several vehicles 904, 906that are mechanically connected with each other to travel along a route902. The vehicles 904 (e.g., the vehicles 904A-D) representpropulsion-generating vehicles, such as vehicles that generate tractiveeffort or power in order to propel the vehicle system along the route902. In an embodiment, the propulsion-generating vehicles can representrail vehicles such as locomotives, but alternatively can representanother type of vehicle. The vehicles 906 (e.g., the vehicles 906A-F)represent non-propulsion generating vehicles, such as vehicles that donot generate tractive effort or power. In an embodiment, thenon-propulsion generating vehicles can represent rail cars or anothertype of vehicle. The route can be a body, surface, or medium on whichthe vehicle system travels, such as a track formed from one or morerails, or another type of route. The number and arrangement of thevehicles 904, 906 is provided as one example, and other numbers and/orarrangements of the propulsion-generating vehicles and/or thenon-propulsion generating vehicles may be used.

The vehicle system includes several vehicle consists 910 (e.g., consists910A-C) formed from one or more propulsion-generating vehicles. In theillustrated example, a lead consist 910A includes thepropulsion-generating vehicles 904A, 904B, a middle consist 910Bincludes the propulsion-generating vehicle 904C, and a remote consist910C includes the propulsion-generating vehicle 904D. Optionally, alarger or fewer number of propulsion-generating vehicles may be includedin one or more of the consists and/or a larger or fewer number ofconsists may be included in the vehicle system. The consists may beseparated from each other by one or more non-propulsion generatingvehicles.

A virtual fence 912 is shown in different locations in the vehiclesystem in FIG. 9. In a first position, the virtual fence is between thelead consist and the middle consist. In a different, second position,the virtual fence is between the middle consist and the remote consist.The fence can move between these or other locations in the vehiclesystem as the vehicle system travels along the route. As the fence ismoved, the propulsion-generating vehicles and/or thenon-propulsion-generating vehicles can be included in (e.g., assignedto) different groups, with the vehicles in the same group using the sameoperational settings, such as the same throttle notch settings, samebrake settings, or the like. For example, in a group ofpropulsion-generating vehicles, the propulsion-generating vehicles mayuse the same throttle notch settings. In a group ofnon-propulsion-generating vehicles and/or propulsion-generatingvehicles, the same brake settings may be used. Different vehicles may beassigned to different groups without physically moving or changing therelative positions of the vehicles in the vehicle system. For example, asingle virtual fence 912 may change positions between the two positionsshown in FIG. 9. Without moving any vehicle in the vehicle system,different vehicles may be assigned to different groups. For example,when the fence 912 is between the vehicles 904B and 906A, then thevehicles 904A, 904B can be assigned to one group while the vehicles904C, 904D are assigned to a different group. Moving the fence 912 toanother position (e.g., between the vehicles 904C and 906C can cause thevehicles 904A, 904B, and 904C to be assigned to one group and thevehicle 904D to be assigned to a different group without changing thelocation or order of the vehicles 904A-E within the vehicle system 100.

The fence can move between the positions of consists, and not thepositions of the propulsion-generating vehicles within a consist, andthe propulsion-generating vehicles on opposite sides of the fence canoperate using different control signals. When the fence moves from timeto time, the configuration of the groups changes, which can result inthe change of the tractive effort generated along the length of thevehicle system, as well as the forces within the vehicle system.

While only a single fence is shown in FIG. 9, alternatively, the vehiclesystem may operate using plural different fences. The description hereinshould not be construed to be limited to using only a single fence.Plural different fences may be used. Optionally, the vehicle system mayoperate using different numbers of fences at different times and/orlocations along the route. The number of permitted fences or theirpossible locations may be referred to as a fence restriction or a groupassignment restriction, and can indicate how many fences and/or vehiclegroups are allowed at an associated time and/or location along the routeor where they may be placed (e.g., inter- and/or intra-consist). Thenumber of permitted fences and/or vehicle groups may be change as afunction of time, location, and/or operator input. For example,different numbers of fences and/or vehicle groupings may be permitted atdifferent times during a trip, at different locations along a route,and/or as selected by an operator of the vehicle system. For example,during a first time period and/or during movement over a first segmentof the route, the vehicle system may operate using a single fence,during a different, second time period and/or during movement over adifferent, second segment of the route, the vehicle system may operateusing two or more fences. Alternatively, the vehicle system may not useany virtual fences, but instead may operate by associating thepropulsion-generating vehicles with different groups at different timesand/or locations along the route.

For example, when the fence is located at a lead-middle position (e.g.,between the lead consist and the middle consist), the middle and remoteconsists are grouped together and operate using the same controlsignals. The propulsion-generating vehicles 904C, 904D may then use thesame throttle notch settings as each other, while thepropulsion-generating vehicles 904A, 904B can use the same throttlenotch settings as each other. But, the throttle notch settings of thepropulsion-generating vehicles 904C, 904D may be different from thethrottle notch settings of the propulsion-generating vehicles 904A,904B. When the fence is located at a middle-remote position (e.g.,between the middle consist and the remote consist), the lead and middleconsists are grouped together and operate at the same control signals.As a result, the propulsion-generating vehicles 904A-C can then use thesame throttle notch settings as each other, while thepropulsion-generating vehicle 904D can use the same or a differentthrottle notch setting.

A trip plan for the vehicle system can be created to designateoperational settings of the propulsion-generating vehicles as a functionof time and/or distance along the route. For example, the trip plan candesignate speeds of the vehicle system as a function of one or more oftime and/or distance along the route. This trip plan may include or beassociated with command profiles that designate operational settings ofthe propulsion-generating vehicles. For example, the command profilescan dictate the throttle notch positions or other settings of thepropulsion-generating vehicles as a function of time and/or distancealong the route. The trip plan may include or be associated with changeindices that dictate locations of the vehicle system along the routeand/or times at which the groups in which the propulsion-generatingvehicles are included changes. Optionally, the trip plan may include orbe associated with change indices that dictate positions of the fence inthe vehicle system at different locations along the route and/or timesat which the position of the fence is to change.

The command profiles and/or change indices may be created by consideringhandling parameters of the vehicle system, such as in-system forces(e.g., coupler forces, or the like) or other handling parametersdescribed above. Controlling these handling parameters (e.g., keepingthe parameters within designated limits) contributes to safe running ofthe vehicle system and to limiting maintenance cost. For example, thelarger the in-system forces are, the more likely it is that couplersbetween the vehicles frequently experience fatigue. The fatigue has alarge impact of the life of a coupler, and the break of a coupler willcause safety concerns and increased cost of maintenance.

The command profiles and change indices may be created by modeling thevehicle system as a “rope model,” which considers the vehicle system asa cascade of connected mass points, with each connection betweenvehicles being modeled as a rigid connection without any dynamic actionof the connection. This model is based on information about the make-upof the vehicle system and the positions of the vehicles in the vehiclesystem, so that the model can be used to estimate the handlingparameters. Optionally, another model may be used, such as a lumped massmodel, a dynamic model, or another model.

By changing which vehicles are included in the different groups and/ormoving the fence during the trip, the handling parameters are furtheraddressed with the freedom to change the group assignments of thevehicles. The handling parameters are expected to improve relative tonot changing which vehicles are included in which groups and/or relativeto not moving the fence, especially in terrain where the grade changes.For example, when the vehicle system is crossing a hill, the groups ofthe vehicles can change and/or the fence can be moved to dictate whichvehicles use the same settings so that, after the lead consist passesthe top of the hill, the lead consist can begin braking and motoring maybe applied in the remote consist. After the middle consist passes thetop of the hill, a braking signal can be applied to the middle consistwhile still providing a motoring signal to the remote consist.

FIG. 10 illustrates a flowchart of a method 1000 for determining commandprofiles and/or change indices that dynamically change group assignmentsof the vehicles and/or fence positions in the vehicle systems shownherein according to one embodiment. The method 1000 can be used togenerate command profiles and/or change indices for use in controllingoperations of the vehicle system.

At 1002, data used to determine command profiles are obtained. This datacan include system data, which represents characteristics of the vehiclesystem. For example, the system data can include a size of the vehiclesystem (e.g., length, mass, weight, etc.), an arrangement or locationsof the propulsion-generating vehicles and/or non-propulsion-generatingvehicles in the vehicle system (e.g., where the vehicles are located inthe vehicle system), or the like. The data that is obtained may includevehicle data, which represents characteristics of the vehicles. Forexample, the vehicle data can include the horsepower (HP) that thevehicles can produce, the braking efforts that the vehicles can produce,and the like. The data that is obtained may include route data, such asthe layout of the route that is to be traveled upon. The layout of theroute can include grades, curvatures, and the like, of the route.

The data that is obtained can include constraint data, such asinformation representative of limitations on how the vehicle system iscontrolled. These limitations can include restrictions on how often orfrequently the group assignments of the vehicles are changed, how oftenof frequently the fence is moved within the vehicle system, limitationson how many throttle notch positions and/or brake settings the vehiclescan use, limitations on how large of a change between notch positions orsettings and/or brake settings can be used, limitations on how manyfences can be used to assign the vehicles to different groups, or thelike.

For example, the notch setting represents the tractive effort that eachvehicle 104 can produce. In rail vehicles, the notch setting may extendfrom −8 to 8, where −8 represents maximum braking effort and 8 representthe maximum motoring effort. These notch settings may be limited tovalues of −8 to 8. Also, the notch command, or control sign, may not beallowed to change simultaneously. The notch command may be permitted toonly change a single notch (e.g., from −8 to −7) in a designated timeperiod (e.g., three seconds). Other data that may be obtained caninclude a trip plan that designates operational settings of the vehiclesystem as a function of time and/or distance along the route. Asdescribed herein, this trip plan can dictate speeds or other settings ofthe vehicle system as a function of time and/or distance.

Additional constraints can include fuel consumption limits, wherecertain operational settings are not permitted for one or morepropulsion-generating vehicles as these settings could cause thevehicles to consume more fuel or to consume fuel at a greater rate thandesired. For example, a propulsion-generating vehicle may not bepermitted to be assigned a notch setting that would cause the vehicle toconsume more fuel than the vehicle is carrying and/or consume fuel at asuch a rate that the vehicle will not have sufficient fuel to complete atrip.

Another operating constraint can include engine derating. One or moreengines of the propulsion-generating vehicles may be derated and unableto generate the horsepower or tractive effort associated with the ratingof the engines. The decreased output or capability of these engines maybe used to limit what operational settings are assigned to differentvehicles to prevent the vehicles from having to operate the engines atlevels that exceed the derated capabilities of the engines.

Another example of an operating constraint can include a notch deltapenalty. Such a penalty can restrict how much and/or how quickly anoperational setting of a vehicle is allowed to change. For example, anotch delta penalty may not allow the throttle notch setting for apropulsion-generating vehicle to change by more than three positions(e.g., throttle notch one to throttle notch four). Instead, the vehiclemay be limited to changing throttle positions by three positions or lessat a time.

Another example of an operating constraint can be a limitation on howfrequently a position of a virtual fence is changed. For example, such aconstraint may not permit a location of a fence in the vehicle system100 to change more frequently than a designated frequency or timeperiod.

Another example of an operating constraint can be a limitation on anumber of fences that can be included in the vehicle system. Forexample, different locations or segments of the route being traveledupon or that are to be traveled upon may have restrictions on the numberof groups to which the vehicles can be assigned. Segments of the routehaving undulations, curves, or the like, may be restricted to fewerfences or vehicle groups than segments of the route having fewerundulations, curves, or the like.

At 1004, handling parameters are determined for different groups of thevehicles and/or different fence positions. In one embodiment, a ropemodel can be used to estimate the expected forces exerted on couplersbetween the vehicles in the vehicle system when the vehicles areassociated with different vehicle group assignments and/or the fence isat different positions at one or more locations along the route. Therope model can assume that the vehicle system includes mass points(which represent the vehicles) connected with connections, such ascouplers, spacings between aerodynamically and/or fluidly coupledvehicles, or the like. The connection may be assumed to be rigid withoutdynamic movements.

The handling parameters can be determined based on at least some of thedata obtained at 1002. As one example, the handling parameters can bebased on a trip plan for the vehicle system. The trip plan can designateoperational settings of the vehicle system as a function of time and/ordistance along the route. For example, the trip plan can dictate speedsat which the vehicle system is to travel at different times and/orlocations along the route. Optionally, the trip plan can dictate othersettings of the vehicle system.

As one example that is not intended to limit all embodiments of thesubject matter described herein, coupler forces may be calculated as thehandling parameters. Alternatively, one or more other handlingparameters may be calculated, estimated, sensed, or the like. In orderto estimate the coupler forces as handling parameters, other forces onthe connected vehicles can be examined. A vehicle may be subject tointernal forces from neighboring vehicles, gravity forces, aerodynamicforces, traction forces, and the like. One of these forces includes dragon a vehicle. The total drag on a moving vehicle can be expressed by thesum of aerodynamic and mechanical forces as follows:

f=a+bv+cv ²  (Equation #19)

where f represents total drag on the vehicle, v represents the speed ofthe vehicle, and a, b, and c are constants determined by experiments(and usually referred to as David coefficient parameters).

Another force that may be exerted on the vehicle can include aresistance force. The resistance force can be based on the location ofthe vehicle along the route, and may be expressed as follows:

f _(p) =f _(g) +f _(c)  (Equation #20)

where f_(p) represents the resistance force, f_(g) represents a gravityforce, and f_(c) represents a curvature resistance force. The gravityforce (f_(g)) may be expressed as follows:

f _(g) =mg sin θ  (Equation #21)

where m represents the mass of the vehicle, g represents thegravitational force, and θ represents the angle at which the vehicle istilting or moving. The curvature resistance force (f_(c)) represents theforce exerted on the vehicle by the vehicle moving along a curvedsection of the route. Because the layout of the route may be known, thiscurvature resistance force (f_(c)) may be previously measured,calculated, or estimated. In one aspect, a distribution of weight ormass of the vehicles in the vehicle system may not be even. For example,the masses of the vehicles in one location or portion of the vehiclesystem may be larger than the masses of the vehicles in other locationsor portions of the vehicle system. Alternatively, the masses of thevehicles may be even throughout the vehicle system, such as the massesof all vehicles 904, 906 being equal or within a designated range of oneanother, such as within 1%, 3%, 5%, 10%, or the like.

The model of the vehicle system may be is described by one or more (orall) of the following expressions:

m _(i) {dot over (v)} _(i) =u _(i) +f ¹⁻¹ −f _(i) −f _(a) _(i) −f _(p)_(i) , i=1,2, . . . , n  (Equation #22)

{dot over (x)} _(j) =v _(j) −v _(j+1) , j=1,2, . . . n−1  (Equation #23)

where m_(i) represents the mass of the i^(th) vehicle in a vehiclesystem including n vehicles, v_(i) represents the speed of i^(th)vehicle, f_(a) _(i) represents the aerodynamic force exerted on thei^(th) vehicle, f_(p) _(i) represents the force exerted on the i^(th)vehicle due to the grade and curvature of the route where the i^(th)vehicle is moving, f_(i) represents the forces between the i^(th) and(i+1)^(th) vehicles, u_(i) represents the force that the i^(th) vehiclegenerates (e.g., which may be zero for a non-propulsion generatingvehicle or the tractive effort generated by a propulsion-generatingvehicle), x_(j) represents the difference in velocities between thej^(th) vehicle and the neighboring (j+1)^(th) vehicle.

One objective of the model can be to reduce in-system forces, as well asthe fuel consumption and/or emission generation of the vehicle system.In one embodiment, a speed profile that is generated to reduce fuelconsumption and/or emission generation may be obtained, and thein-system forces on the vehicles may be modeled using the speedsdesignated by such a profile. In scheduling the open loop controller, itis assumed that the desired speed is reached and held. The objective ofthe model can be expressed as:

$\begin{matrix}{J = {\sum\limits_{i = 1}^{n}f_{i}^{2}}} & \left( {{Equation}\mspace{14mu} {\# 24}} \right)\end{matrix}$

where J represents a cost function representative of in-system forces ofthe vehicle system and f_(i) represents the coupler force of the i^(th)vehicle. Different notch settings can be examined for differentlocations along the route in order to calculate different values of thecost function (J), subject to the constraints described above.

The cost function (J) can be used to identify the groups of the vehiclesand/or the positions of the fence within the vehicle system at differentlocations along the route and/or times of the trip. As used herein, theterm “potential change point” refers to a location along the routeand/or time during a trip of the vehicle system where the handlingparameters are determined, or the groups of vehicles and/or fencepositions may change. The potential change points of a trip mayrepresent designated, periodic locations, such as every kilometer, everyfew kilometers, very few fractions of a kilometer, or other distance,along a route. Optionally, the potential change points can representdesignated, periodic times, such as every second, minute, hour, or thelike. In one aspect, the potential change points may be defined by anoperator, and/or may not be periodic in location.

The vehicle group assignments and/or fence positions may not change atevery potential change point. The vehicle system may travel throughseveral potential change points without changing the vehicle groupassignments or fence positions. As used herein, the phrase “potentialchange point along the route” may represent a geographic location or anelapsed time during a trip. In one embodiment, group assignments of thevehicles and/or a position of a fence are chosen where the cost function(J) has a minimum value among all possible group assignments of thevehicles and/or positions of the fence at a location along the route, orwhere the cost function (J) has a lower value than one or more othergroup assignments of the vehicles and/or positions of the fence at thepotential change points along the route. This can be described as acontrol problem that is expressed as follows:

$\begin{matrix}\begin{matrix}{{\min\limits_{s}{J(s)}} = {\min\limits_{s}{\sum\limits_{i = 1}^{n}{{f_{i}^{2}(s)}s}}}} \\{{= 1},2,\ldots \mspace{14mu},v}\end{matrix} & \left( {{Equation}\mspace{14mu} {\# 25}} \right)\end{matrix}$

where s represents possible positions of the fence, which also candictate which vehicles are in which groups. For example, the vehiclesbetween two fences, between a fence and a leading end of the vehiclesystem, or the vehicles between a fence and a trailing end of thevehicle system may be included in a group. As a result, the position ofthe fence in the vehicle system and/or the group assignments of thevehicles at different potential change points of the vehicle systemalong the route can be determined based on the in-system forces, asdescribed above.

In one embodiment, the handling parameters that are calculated may benormalized and/or bunching power (e.g., horsepower) metrics may becalculated. With respect to normalizing the in-system forces (e.g., thecoupler forces), these calculated forces may be normalized bymultiplying or dividing the forces by a factor. In one embodiment, theseforces may be normalized using the following expression:

$\begin{matrix}{{J_{force}\left( {k,i} \right)} = \frac{{J_{IDP}\left( {k,i} \right)} - {\min\limits_{i}\left( {J_{IDP}\left( {k,i} \right)} \right)}}{thresh}} & \left( {{Equation}\mspace{14mu} {\# 26}} \right)\end{matrix}$

where J_(force)(k, i) represents a normalized value of an in-systemforce (e.g., a coupler force) that is calculated as being exerted on acoupler at position of the fence that is at the i^(th) vehicle at apotential change point along the route defined by the k^(th) potentialchange point, J_(IDP)(k, i) represents a combination of the calculatedin-system forces, thresh represents a designated constant value, andmin_(i)(J_(IDP)(k,i)) represents a minimum value of the in-system forcescalculated for all positions of the fence or all group assignments ofthe vehicles at all potential change points. The k potential changepoints along the route can represent designated potential change pointsalong the route or during the trip. These potential change pointsoptionally can be referred to as “mesh points.” Alternatively,min_(i)(J_(IDP)(k,i)) can represent a value of the in-system forces thatis less than one or more, but not all, of the in-system forcescalculated for possible positions of the fence and/or all groupassignments of the vehicles at possible potential change points. In oneaspect, J_(IDP)(k, i) can represent a sum of squared coupler forces thatare calculated for a position of the fence that is at the i^(th) vehicleat a potential change point along the route defined by the k^(th)potential change point. Optionally, J_(IDP)(k, i) can represent anothercombination of these forces. In another embodiment, the in-system forcescan be normalized in another manner, such as by dividing the calculatedforces by a maximum calculated force, a minimum calculated force, adesignated value, another calculated force, or the like.

Optionally, bunching power metrics can be calculated. The bunching powermetrics can represent the amount of tractive effort or power that iscalculated as being generated by different groups of thepropulsion-generating vehicles at different positions of the fence atthe different potential change points. In one embodiment, the bunchingpower metrics can be calculated using the following expression:

$\begin{matrix}{{J_{bunch}\left( {k,i} \right)} = \frac{{HP}_{bunching}\left( {k,i} \right)}{\max \left( {{abs}({THP})} \right)}} & \left( {{Equation}\mspace{14mu} {\# 27}} \right)\end{matrix}$

where J_(bunch)(k, i) represents the bunching power metric for thevehicle system 100 when the fence 112 is at a position at the i^(th)vehicle and the vehicle system 100 is at the k^(th) potential changepoint, HP_(bunch)(k, i) represents the differential combined poweroutput (e.g., the difference in power on opposite sides of the fence)generated by the propulsion-generating vehicles when the fence is at aposition at the i^(th) vehicle and the vehicle system is at the k^(th)potential change point, and max(abs(THP)) represents the maximum valueof the total power (e.g., horsepower) that can be generated by thepropulsion-generating vehicles in the vehicle system. Optionally,max(abs(THP)) can represent another value that is not the maximum valueof the total power (e.g., horsepower) that can be generated by thepropulsion-generating vehicles in the vehicle system.

Alternatively, the handling parameters may be determined in anothermanner. As described above, the handling parameters optionally caninclude coupler parameters, terrain excitation parameters, nodeparameters, neighboring velocity parameters, or based on natural forces.In one aspect, the handling parameters may be determined without havinggrade information about the route being traveled upon or that is to betraveled upon. In such a situation, the handling parameters can bedetermined by measuring forces exerted on the couplers (e.g., using aforce sensor connected with a coupler or to the vehicles connected bythe coupler), by measuring separation distances between neighboringvehicles (e.g., with decreasing separation distances indicating that acoupler between the vehicles may be transitioning from a tension orslack state to a compressed state and with increasing separationdistances indicating that a coupler between the vehicles may betransitioning from a compressed or slack state to a state of tension).Optionally, the handling parameters can be determined based on energydifferences. For example, the total energy of the vehicle system may bea combination of kinetic energy and potential energy. The potentialenergies of the vehicle system at various locations can be estimated ordetermined, such as based on the altitude at which the vehicle system islocated as obtained from a global positioning system (GPS) receiver. Thekinetic energy can be estimated or determined based on the speed atwhich the vehicle system is moving. The combined kinetic and potentialenergies can be determined for different vehicles in the vehicle system.If the combined kinetic and potential energies at one or more vehicleschanges over time, then the differences between the total energies ofthe vehicle system can indicate changing energies stored in or exertedupon couplers connected to the vehicle(s) as forces. These changingenergies or coupler forces can be used as the handling parameters forthe various vehicles.

With the handling parameters (e.g., coupler forces) being calculated ordetermined for different positions of the fence at different potentialchange points along the route at 1004, the method 1000 can proceed to1006. At 1006, a value of a variable k is set to 1. This variable k canhave different values to represent different potential change pointsalong the route. For example, if the route includes 100 differentpotential change points (e.g., mesh points), then the variable k canchange in value from one to 100. Alternatively, this variable can haveother values. The method 1000 can proceed by changing the values of k toexamine the calculated in-system forces and/or bunching power metrics atdifferent potential change points along the route. As described below,the method 1000 may determine to change or move a position of the fence(or otherwise change which vehicles are assigned to which groups) at oneor more of these potential change points as the method 1000 examines thehandling parameters.

At 1008, a determination is made as to whether the vehicles in one ormore of the groups and/or the position of one or more fences was lastchanged within a designated period of time. For example, the method 1000can examine previous potential change points and the times at which thevehicle system is expected to travel through these potential changepoints (e.g., using a designated speed of a previously determined tripplan or speed profile) to determine if the group assignments of thevehicles and/or the position of one or more fences in the vehicle systemchanged in less than a threshold dwell time period ago. If the vehiclegroup assignments and/or fence position was changed relatively recently(e.g., in less than the threshold dwell time period), then the groupassignments may remain the same and/or the position of the one or morefences may not be moved again to avoid changing the group assignmentsand/or fence positions too quickly.

For example, the dwell time period may be set to one minute to ensurethat the vehicle group assignments and/or fence positions do not changemore than once per minute. Alternatively, another dwell time period maybe used. If the vehicle group assignments and/or fence positions changedrecently within this dwell time period, then flow of the method 1000 canproceed to 1010. On the other hand, if it has been a longer than thethreshold dwell time period since the vehicle group assignments and/orfence positions were last changed, then the vehicle group assignmentsand/or fence positions may be able to be changed again. As a result,flow of the method 1000 can proceed to 1012.

At 1010, the vehicle group assignments and/or fence positions are notchanged when the vehicle system 1000 is at the k^(th) potential changepoint along the route. For example, the method 1000 may have determinedto change the vehicle group assignments and/or fence positions toorecently to safely allow for the vehicle group assignments and/or fencepositions to be changed again at the k^(th) potential change point. Flowof the method 1000 can proceed from 1010 toward 1016, as describedbelow.

At 1012, a determination is made as to whether there is at least athreshold benefit to changing the vehicle group assignments (e.g., bymoving the fence positions) when the vehicle system is at the k^(th)potential change point along the route. The handling parameters that arecalculated, estimated, or sensed can be examined in order to determineif changing the vehicle group assignments at the k^(th) potential changepoint results in an improvement in the vehicle handling parameters thatis at least as large as the threshold benefit (where the thresholdbenefit represents a magnitude of the handling parameters). As oneexample, the coupler forces that are estimated as the handlingparameters if the position of the fence is moved at the k^(th) potentialchange point and the coupler forces that are estimated as occurringduring an upcoming period of time in the trip (e.g., twice the time ofthe threshold dwell period of time or another time period) are examined.

If changing the vehicle group assignments at the k^(th) potential changepoint results in the handling parameters improving over this upcomingperiod of time by at least the amount of the threshold benefit, thenchanging the vehicle group assignments at the k^(th) potential changepoint may be desirable. For example, if changing the vehicle groupassignments results in a calculation of the coupling forces decreasingby at least a designated, non-zero threshold amount, then changing thevehicle group assignments occurs. Optionally, the handling parametersmay be examined to determine if changing the vehicle group assignmentsresults in a calculated increase of the handling parameters by at leasta threshold benefit amount. As a result, flow of the method 1000 canproceed to 1012.

On the other hand, if changing the vehicle group assignments at thek^(th) potential change point does not result in the handling parametersimproving over the upcoming period of time by at least the amount of thethreshold benefit, then changing the vehicle group assignments at thek^(th) potential change point may not be desirable. For example, thereduction in the coupler forces may be sufficiently small that keepingthe current position of the fence may be desired over moving the fence.As a result, flow of the method 1000 can proceed to 1010. At 1010, thevehicle group assignments at the k^(th) potential change point mayremain the same. For example, the fence can remain at the same positionas the (k−1)^(th) potential change point (or may not move if the valueof k is one).

At 1014, a sequence of changes in the vehicle group assignments isdetermined for when the vehicle system is at the k^(th) potential changepoint. For example, a sequence of movements of the position of the fencecan be determined for when the vehicle system is at the k^(th) potentialchange point. The method 1000 can determine this order at 1014.

A sequence of changes in the vehicle group assignments can berepresented as different groups of the vehicles at different potentialchange points of the vehicle system along the route. The groups can bedifferent at different potential change points by assigning the vehiclesto different groups, without physically moving or changing the positionsof the vehicles within the vehicle system. For example, a sequence mayinclude a first group of the vehicles (e.g., the vehicles 904A, 904B ina first group and the vehicles 904C, 904D in a second group) when thevehicle system is at a first potential change point along the route;followed by a different, second group of the vehicles (e.g., the vehicle904A in the first group, the vehicles 904B, 904C in the second group,and the vehicle 904D in a third group) when the vehicle system is at adifferent, second potential change point along the route; followed by adifferent, third group of the vehicles (e.g., the vehicles 904A, 904B,904C in the first group and the vehicle 904D in the second group) whenthe vehicle system is at a different, third potential change point alongthe route; and so on. Optionally, the sequence of changes in the vehiclegroup assignments can be represented by a sequence of changes in fencepositions. With respect to the preceding example, such a sequence mayinclude a first fence between the vehicle 904B and the vehicle 904C whenthe vehicle system is at the first potential change point along theroute; the first fence between the vehicle 904A and the vehicle 904B,and a second fence between the vehicle 904C and the vehicle 904D whenthe vehicle system is at the second potential change point along theroute.

Alternatively, the groups can be different at different potential changepoints by physically moving one or more of the vehicles so that thepositions of the vehicles changes within the vehicle system. Forexample, a sequence may include the vehicles 904A, 904B in a first groupand the vehicles 904C, 904D in a second group when the vehicle system isat a first potential change point along the route; followed by adifferent grouping of the vehicles that results from switching thepositions of the vehicles 904B and 904C such that the vehicles 904A,904C are in one group and the vehicles 904B, 904D are in another group.

Optionally, the groups can be different at different potential changepoints by adding one or more vehicles to the vehicle system and/orremoving one or more vehicles from the vehicle system. For example, asequence may include the vehicles 904A, 904B in a first group and thevehicles 904C, 904D in a second group when the vehicle system is at afirst potential change point along the route. At a subsequent secondpotential change point, a vehicle may be added to the vehicle system(e.g., a helper vehicle or helper locomotive) and assigned to a groupthat includes one or more of the vehicles 904. At another, thirdpotential change point, the vehicle that was added at the secondpotential change point may be removed from the vehicle system and/oranother vehicle may be added to the vehicle system. At another, fourthpotential change point, one or more of the vehicles 904 may be removedfrom the vehicle system.

In one embodiment, the assignments of the vehicles to different groupscan change at different potential change points by separating thevehicle system into two or more smaller vehicle systems. Due to asegment of the route having several undulations and/or curves (oranother reason), the handling parameters of the vehicle system may beimproved by separating the vehicle system into two or more separatevehicle systems that travel over the segment of the route as separate,non-connected vehicle systems and then combine back together to form theoriginal vehicle system after traveling over the segment of the route.The handling parameters may be improved when separating the vehiclesystem into smaller vehicle systems relative to the larger vehiclesystem traveling over the segment of the route without dividing thevehicle system into the smaller vehicle systems. As one example, priorto reaching a first potential change point, the vehicle system 900 maytravel with the vehicles 904A-D and 906A-F being mechanicallyinterconnected with each other such that the vehicle system 900 moves asa unit. Upon reaching the first potential change point, it may bedetermined that the handling parameters of the vehicle system 900 can beimproved by separating the vehicles 904A, 904B, 906A, and 906B from thevehicles 904C, 906C, 906D, 906E, 906F, and 904D such that two smallervehicle systems are formed. The first smaller vehicle system can beformed by the vehicles 904A, 904B, 906A, and 906B and the second smallervehicle system can be formed by the vehicles 904C, 906C, 906D, 906E,906F, and 904D. Alternatively, three or more smaller vehicle systems canbe formed. The separate, smaller vehicle systems can travel along theroute to a subsequent potential change point, where it may be determinedthat the handling parameters of the smaller vehicle systems can beimproved by re-combining the smaller vehicle systems into the largervehicle system 900 (and/or assigning the vehicles 904 to differentgroups). The smaller vehicle systems may then be re-combined into thelarger vehicle system 900.

In one embodiment, the method 1000 can employ an “exhaustive search”technique to identify the sequence of changes to the vehicle groupassignments. This technique can involve estimating the vehicle handlingparameters (e.g., coupler forces or other parameters) for all differentpermutations of the possible sequences of changes in the vehicle groupassignments (e.g., changes in the positions of the fence) during anupcoming designated period of time (e.g., twice the threshold dwell timeperiod or another time period). The sequence of changes in the vehiclegroup assignments that results in estimated handling parametersimproving (e.g., decreasing or increasing, as appropriate) by the mostor more than one or more other sequences may be identified as a selectedsequence. For example, the sequence of changes in the fence positionsthat results in the estimated coupler forces being less than all othersequences or that are less than at least a designated number of othersequences may be identified as the selected sequence.

In another embodiment, the method 1000 can employ a “dynamicprogramming” technique to identify the selected sequence of changes tothe vehicle group assignments. This technique can involve estimating thehandling parameters for many, but less than all, different permutationsof the possible sequences of changes in the group assignments of thevehicles during the upcoming designated period of time. In contrast tothe “exhaustive search” technique, the “dynamic programming” techniquemay not examine certain designated sequences of changes in the vehiclegroup assignments. The “dynamic programming” technique may excludecertain sequences of changes from consideration that are previouslyidentified as undesirable or non-optimal sequences of changes. Thesesequences may be identified by an operator of a system that performs themethod 1000, may be identified by previous generations of commandprofiles for the vehicle system, or may be identified in another manner.Among the sequences that are examined in the “dynamic programming”technique, the sequence of changes in the vehicle group assignments thatresults in estimated handling parameters that are less or larger thanother sequences (as appropriate) or that are less than or greater than(as appropriate) at least a designated number of other sequences may beidentified as the selected sequence. Some of the sequences that may notbe examined may include those sequences that result in changes in fencepositions that occur more frequently than a designated limit or exceedthe fence restrictions, changes in operational settings of one or morevehicles that are larger than one or more designated limits, changes inthe fence positions and/or operational settings that previously wereidentified as causing an undesired change in handling parameters, or thelike.

In another embodiment, the method 1000 can employ a “complete tripdynamic programming” technique to identify the selected sequence ofchanges to the vehicle group assignments. This technique can involveestimating the handling parameters for many, but less than all,different permutations of the possible sequences of changes in thevehicle group assignments during a period of time that is longer thanthe upcoming designated period of time. For example, this technique canapply the “dynamic programming” technique described above to the entiretrip of the vehicle system or to another period of time that is longerthan the upcoming designated period of time.

In another embodiment, the method 1000 can employ a “hybrid” techniqueto identify the selected sequence of changes to the vehicle groupassignments. This technique can involve examining the handlingparameters for different vehicle group assignments (e.g., at differentfence positions) at different potential change points along the routeand selecting the sequence that reduces or minimizes (or increases ormaximizes, as appropriate) the handling parameters over a designatedperiod of time (e.g., the threshold dwell time period) following achange in the vehicle group assignments.

With continued reference to the method 1000 shown in FIG. 10, FIG. 11illustrates a table 1100 demonstrating possible sequences of changingthe vehicle group assignments in the vehicle system according to oneembodiment. The handling parameters estimated from changing the vehiclegroup assignments according to the different sequences may be used todetermine the selected sequence. The table 1100 includes severalpotential change point columns 1102 representative of different upcomingpotential change points along the route. The table 1100 also includesseveral sequence rows 1104 representative of different sequences ofchanging the vehicle group assignments in the vehicle system. In each ofthe sequence rows 1104, one or more “X” symbols are shown. The locationof the X symbols indicates the potential change point or potentialchange points in the corresponding sequence at which the vehicle groupassignments are changed in that sequence when the vehicle system arrivesat or passes through the potential change points. For example, the firstsequence can include changing the position of the fence at the k^(th)and (k+4)^(th) potential change points, the fifth sequence can includechanging the position of the fence at the (k+1)^(th) and (k+5)^(th)potential change points, and so on.

Several movement ban boxes 1106 are overlaid on the table 1100. Theseboxes 1106 represent the time periods over which the vehicle groupassignments are not allowed to change following a previous change in thevehicle group assignments. For example, these boxes 1106 can correspondto the dwell time period over which the fence positions do not changefollowing a preceding change in the fence positions. With respect to thethird sequence, the box 1106 begins at the k^(th) potential change pointalong the route (the potential change point of the vehicle system alongthe route where the vehicle group assignments are changed, such as bychanging the position of the fence) and extends to the (k+3)^(th)potential change point along the route to indicate that the vehiclegroup assignments cannot be moved again until at least the (k+4)^(th)potential change point along the route. Other sequences include similarboxes 1106. With respect to the boxes 1106 in the latter potentialchange points, the length of the boxes 1106 is reduced in FIG. 11 due tosize constraints of the table 1100. But, these boxes 1106 would extendto additional potential change points not shown in the table 1100.

The “hybrid” technique of identifying the selected sequence of changesto the vehicle group assignments (e.g., sequence of movements of thefence) can determine which of the sequences improves the handlingparameters (e.g., by reducing the in-train forces) while optionallypenalizing changes in the vehicle group assignments and/or penalizingbunching horsepower in the vehicle system. In one embodiment, theestimated handling parameters for a sequence of changes to the vehiclegroup assignments may be expressed as follows:

$\begin{matrix}{J = {{J\; 1} + \frac{J\; 2}{A} + {J\; 3*{movePenalty}} + {J\; 4*{bunchPenalty}}}} & \left( {{Equation}\mspace{14mu} {\# 28}} \right)\end{matrix}$

where J represents the estimated handling parameters for a sequence(e.g., the coupler forces or other parameters), J1 represents a maximumvalue of J_(force)(k, i) calculated for the different potential changepoints of the vehicle system along the route and different groupassignments of the vehicles (e.g., different fence positions, asdescribed above), J2 represents a mean value of the values ofJ_(force)(k, i) calculated for the different potential change points anddifferent group assignments of the vehicles (e.g., different fencepositions), J3 represents a sum of the absolute values of changes inpositions of the fence (e.g., which correspond or are determined fromthe changes in group assignments of the vehicles), and J4 represents themaximum of the absolute values of J_(bunch)(k, i) for the vehicle systembefore and after each change in vehicle group assignments. Optionally,J1 may represent a value of J_(force)(k, i) that is larger than one ormore other values of J_(force)(k, i), but not necessarily the maximumvalue. Alternatively, J2 can represent a median or other value ofJ_(force)(k, i) calculated for the different potential change pointsalong the route and different vehicle group assignments. With respect toJ3, this variable can be calculated by determining how far (e.g., interms of number of potential change points, number of vehicles, distancealong the length of the vehicle system, or otherwise) that one or morefences are moved between changes in the vehicle group assignments. Forexample, if a change in vehicle group assignments would correspond tomoving a fence by a designated distance, then this designated distancecan be used to calculate J3. J3 can represent a combination of how farthe fence is being moved within a sequence being examined. Optionally,J4 can represent a value of J_(bunch)(k, i) for the vehicle systembefore and after each change in the vehicle group assignments that islarger than one or more other values of J_(bunch)(k, i), but that is notnecessarily the largest value. The movePenalty and bunchPenaltyvariables may have designated values that are based on how large thevalues of J_(force)(k, i) are for a sequence. For example, for largervalues of J_(force)(k, i), such as normalized values that exceed one,the value of the movePenalty and/or bunchPenalty decreases (such as toone or zero). For smaller values of J_(force)(k, i), such as normalizedvalues that are one or less, movePenalty and/or bunchPenalty may haveincreased greater than one.

The value of J can be calculated for each sequence, or at least pluraldifferent sequences. The values of J can be compared to determine whichsequence yields a value of J that is less than all other sequences, orthat is less than one or more other sequences, but not necessarily allsequences. The sequence having the lower or lowest value of J can beidentified as the selected sequence. If the values of J for thesequences are less than one, then the vehicle group assignments and/orthe fence positions may not be changed for the k^(th) potential changepoint along the route.

The selected sequence may then be used to determine when and/or wherealong the route to change the vehicle group assignments. For example, ifthe eighth sequence in the table 1100 is identified as the selectedsequence, then the vehicle group assignments or position of the fencemay change when the vehicle system reaches the (k+2)^(th) potentialchange point and again when the vehicle system reaches the (k+6)^(th)potential change point (as indicated by the “X's” in the table 1100).

Optionally, the selected sequence can be used to determine a makeup ofthe vehicle system. For example, different selected sequences can bedetermined for different vehicle systems, with the different vehiclesystems having different propulsion-generating vehicles 904 (e.g.,different numbers of the vehicles 904, different types of the vehicles904, etc.), different non-propulsion-generating vehicles 906 (e.g.,different numbers of the vehicles 906, different types of the vehicles906, different cargo being carried by the vehicles 906, etc.). Thelocations, numbers, types, or the like, of the vehicles 904, 906 in avehicle system can be referred to as a vehicle arrangement or make-up ofthe vehicle system. Different sequences may be determined for two ormore different vehicle arrangements. Depending on which sequences havethe best or better handling parameters than one or more other sequences,the vehicle arrangement associated with the sequence or sequences havingthe better handling parameters may be used to form the vehicle system.

Returning to the description of the flowchart of the method 1000 shownin FIG. 10, at 1016, a determination is made as to whether the currentvalue of k is equal to the total number of potential change points inthe trip. For example, a determination may be made as to whether asequence for changing vehicle group assignments or fence positions hasbeen selected for all of the designated potential change points (or atleast a designated amount of the designated potential change points)along the route. If a sequence has been selected for the designatedpotential change points, then flow of the method 1000 can proceed to1020. Otherwise, additional potential change points along the route mayneed to be examined to determine whether to change vehicle groupassignments and/or fence positions, and/or to determine the sequence touse in changing the vehicle group assignments and/or fence positions. Asa result, flow of the method 1000 can proceed toward 1018.

At 1018, the value of k is increased by one. For example, the value of kmay be changed and flow of the method 1000 can return to 1008 so thatthe determination of whether to change vehicle group assignments and/orfence positions, and/or the identification of the sequence in which tochange the vehicle group assignments and/or fence positions can beperformed for another potential change point along the route.

At 1020, command profiles and/or change indices are generated using theselected sequences. The command profiles can include operationalsettings for inclusion in and/or use with a trip plan. The operationalsettings can indicate which throttle notch positions are to be used forwhich propulsion-generating vehicles and/or groups of thepropulsion-generating vehicles at various locations along the route(e.g., at potential change points and/or other locations along theroute), the brake settings of the vehicles 904 and/or 906, the speeds ofthe vehicles 904 and/or 906, or the like.

The change indices can include position indices and/or time indices. Theposition indices can indicate the potential change points along theroute at which the operational settings are to be used. The operationalsettings may be designated so that one or more groups of the vehicleshave the same operational settings at the same potential change points.As a result, the operational settings and the corresponding potentialchange points designated by the command profile can arrange the vehiclesinto groups and/or establish virtual fences between different groups ofthe vehicles, as described above. Because the operational settings andassignments of the vehicles to different groups may not change at everysingle potential change point along the route for a trip, the number ofposition indices in a plan may be smaller than the number of potentialchange points along the route for the trip.

The time indices can indicate the times during travel of the vehiclesystem along the route at which the corresponding operational settingsare to be used. The operational settings may be designated so that oneor more groups of the vehicles have the same operational settings at thesame times. As a result, the operational settings and the correspondingtimes designated by the command profile can arrange the vehicles intogroups and/or establish virtual fences between different groups of thevehicles, as described above. In one aspect, the position indices may beused in place of the time indices, or the time indices may be used inplace of the position indices. Alternatively, both the position indicesand the time indices may be used.

The command profiles, position indices, time indices, and/or trip plancan then be communicated to the vehicle system in order to direct anonboard operator how to control the propulsion-generating vehicles, toautomatically control the propulsion-generating vehicles, or the like.The vehicle system may then travel on the route for the trip using theoperational settings, position indices, and/or time indices to changevehicle group assignments and/or fence positions during the trip.

In another embodiment, the selected sequences may be determined bygrouping different potential change points along the route having thesame vehicle group assignments and/or fence positions together. Withcontinued reference to the flowchart of the method 1000 shown in FIG.10, FIG. 12 illustrates examples of handling parameters (e.g.,J_(force)(k, i)) calculated for three different vehicle groupassignments or fence positions according to one embodiment. The valuesof the handling parameters are represented by parameter curves 1200,1202, 1204 that are shown alongside a horizontal axis 1206 and avertical axis 1208. The horizontal axis 1206 represents differentpotential change points along the route and the vertical axis 1208represents different values of the handling parameter. The parametercurve 1200 represents values of the handling parameter with a firstvehicle group or first fence position (e.g., where the fence is locatedbetween the consist 910A and the consist 910B). The parameter curve 1202represents values of the handling parameter with a different, secondvehicle group or a different, second fence position (e.g., where thefence is located between the consist 910B and the consist 910C). Theparameter curve 1204 represents values of the handling parameter with adifferent, third vehicle group or a third position of the fence (e.g.,the fence located behind the consist 910C or between the consist 910Cand the trailing end of the vehicle system). “X” symbols are shown alongthe parameter curves 1200, 1202, 1204 to represent the calculated valuesof the handling parameters at the different potential change pointsalong the route for the different vehicle group assignments and/or fencepositions.

With the values of the handling parameter calculated for the differentvehicle group assignments and/or fence positions at the differentpotential change points along the route, a determination is made as towhether segments of potential change points along the route having thesame vehicle group assignments or fence positions exist, or if segmentsof potential change points along the route having values of the handlingparameters (e.g., normalized values) that are less than a designatedthreshold value 1216 (e.g., one or another value) exist.

In the illustrated example, first, second, and third segments 1210,1212, 1214 are identified based on the values of the handlingparameters. The first segment 1210 can be identified based on the valuesof handling parameters in the third parameter curve 1204 exceeding thethreshold value 1216 across consecutive potential change points alongthe route (e.g., potential change points k, (k+1), and (k+2)). The thirdsegment 1214 can be identified based on the values of the handlingparameters in the first parameter curve 1200 exceeding the thresholdvalue 1216 across consecutive potential change points along the route(e.g., potential change points (k+5), (k+6), (k+7)). The second segment1212 can be identified based on the values of the handling parametersbeing less than the threshold value 1216 in consecutive potential changepoints (e.g., mesh points (k+3), (k+4)).

In one embodiment, the identified segments 1210, 1212, 1214 are examinedto determine if the segments 1210, 1212, 1214 are sufficiently long. Forexample, the number of consecutive potential change points in a segmentmay be compared to a threshold of consecutive potential change points,such as three or another value. If the number of consecutive potentialchange points in a segment does not meet or exceed this threshold value,then the segment may be merged into another, neighboring segment. If thenumber of consecutive potential change points in a segment does meet orexceed the threshold value, then the segment may be used to create theselected sequence of changes to the vehicle group assignments and/orchanges to the fence positions. This comparison to a threshold value canbe used to ensure that the vehicle group assignments and/or fencepositions are not changed too frequently.

With respect to the potential change points along the route at which thevalues of the handing parameters do not exceed the threshold value 1216and/or the consecutive potential change points that are insufficientlylong to define a separate segment (as described above), these potentialchange points may be merged into one or more neighboring segments. Thesegment of these potential change points may be referred to as a “To BeDetermined” or “TBD” segment. In the example shown in FIG. 12, thesegment 1212 may be a TBD segment because the values of the handlingparameters are less than the threshold value 1216 and/or because thenumber of potential change points along the route in the segment 1212does not meet or exceed the threshold of consecutive potential changepoints.

In order to determine which neighboring segment 1210, 1214 of the TBDsegment 1212 to merge the TBD segment 1212 into, a determination is madeas to whether the neighboring segments 1210, 1214 on opposite sides ofthe TBD segment 1212 are associated with the same vehicle groupassignments and/or fence positions. In the illustrated example, thesegment 1210 is associated with the propulsion-generating vehicles 904A,904B, 904C, 904D being in the same group (e.g., or the third position ofthe fence, which is behind the trailing consist 910C) while the segment1214 is associated with the propulsion-generating vehicles 904A, 904Bbeing in one group and the propulsion-generating vehicles 904C, 904Dbeing in another group (e.g., or the first position of the fence, whichis between the leading consist 910A and the middle consist 910B).Therefore, the neighboring segments 1210, 1214 of the TBD segment 1212have different vehicle groupings and/or fence positions. As a result,the TBD segment 1212 is not merged into the segment 1210 or the segment1214. If, on the other hand, the segments 1210, 1214 were associatedwith the same vehicle group assignments and/or fence positions as theTBD segment 1212, then the TBD segment 1212 could be merged into thesegment 1210 and/or the segment 1214 to produce a larger segmentcomprised of the segments 1210, 1212, and/or 1214.

If the neighboring segments of a TBD segment are not associated with thesame vehicle group assignments or fence positions (as is the case in theexample shown in FIG. 12), then a determination is made as to whetherseveral TBD segments have been identified. If several TBD segments havebeen identified, then the TBD segments can be sorted in an order, suchas longest to shortest in length (in terms of consecutive potentialchange points in the various TBD segments, distance along the routeencompassed by the consecutive potential change points, or the like).The TBD segments can then be examined for merging into other segments inorder from the longer TBD segments to the shorter TBD segments.Alternatively, the TBD segments may be examined in another order.

For a TBD segment being examined for merger into a neighboring segment,the number of consecutive potential change points in the segments thatneighbor the TBD segment is examined. For example, if one of theseneighboring segments has a number of consecutive potential change pointsthat is less than the threshold number of potential change points, butthat would have a number of consecutive potential change points that isat least as large as this threshold number, then the TBD segment ismerged into this neighboring segment. For example, if the thresholdnumber of potential change points is three and the segment 1214 only hadtwo potential change points (instead of the three potential changepoints shown in FIG. 12), then the TBD segment 1212 could be merged intothe segment 1214 so that the merged segment would include fiveconsecutive potential change points. Otherwise, the TBD segment is leftwithout merging the TBD segment into any neighboring segment.

The remaining segments, which may include segments having values of thehandling parameters that exceed the threshold value 1216, mergedsegments, and TBD segments that are not merged with other segments, arethen used to create the selected sequence of changes to the vehiclegroup assignments and/or fence positions. At the potential change pointsof the trip that are included in the segments having values of thehandling parameters that exceed the threshold value 1216, the vehiclegroup assignments and/or fence positions at those potential changepoints along the route can be the vehicle group assignments and/or fencepositions associated with the values of the handling parameters thatexceed the threshold value 1216.

For example, the vehicle group assignments and fence positions at thepotential change points k, (k+1), and (k+2) in the first segment 1210includes the vehicles 904A, 904B, 904C, and 904D in the same group(e.g., with the fence 912 in the third position between the trailingconsist 910C and the trailing end of the vehicle system) due to thevalues of the handling parameters in the parameter curve 1204 beingrelatively large. The vehicle group assignments and fence position atthe potential change points (k+3) and (k+4) in the TBD segment 1212 canremain at the same as the potential change points k, (k+1), and (k+2)from the first segment due to the TBD segment 1212 remaining separatefrom and not merged into other neighboring segments. For example, asdescribed above, when the in-system forces are relatively low (e.g., forvalues of J_(force)(k, i) that do not exceed the threshold value 1216),the vehicle group assignments and/or fence positions may remain the sameand not change due to the benefit of changing the vehicle groups and/orfence positions being relatively small. The vehicle group assignmentsand/or fence positions may then change to the vehicles 904A, 904B beingin one group and the vehicles 904C, 904D being in another group (e.g.,with the fence 912 between the leading and middle consists 910A, 910B)at the (k+5) potential change point along the route. The vehicle groupassignments and fence position may remain the same at least through the(k+6) and (k+7) potential change points due to the values of the handingparameters in the parameter curve 1200 being relatively large (e.g.,greater than the threshold). The sequence in which the vehicle groupassignments and/or fence positions change between these segments candefine the selected sequence. The command profiles, position indices,and/or time indices of the vehicle group assignments and/or fencepositions can then be generated using the selected sequence, similar toas described above.

While the foregoing description focuses on changing vehicle groupassignments and/or fence positions within a vehicle system having aconstant number and/or arrangement of vehicles 904, 906, optionally, thevehicle group assignments and/or fence positions may change by adding orremoving one or more vehicles. For example, a selected sequence mayinclude adding a propulsion-generating vehicle 904 to the vehicle system(e.g., a helper locomotive) to provide additional tractive effort at aselected potential change point. The vehicle group assignments and/orfence positions may change when this additional vehicle is added. Asanother example, a selected sequence may include removing vehicle 904and/or 906 from the vehicle system at a selected potential change point.The vehicle groups and/or fence positions may change when this vehicleis removed.

In one embodiment, the trip plan, command profiles, change indices,and/or time indices may be determined without having the route datadescribed herein. For example, the grades, curvatures, or the like, ofthe route to be traveled along for a trip may not be available or onlysome of this data may be available for determining fence positions,assignments of the vehicles to different groups, determining operationalsettings, etc. The fence positions, vehicle assignments to differentgroups, operational settings, etc. may be determined based on dataobtained onboard the vehicles during movement along the route. Forexample, the grade, curvature, or the like, of the route can bedetermined using positional data obtained by the vehicle system orvehicles, such as by using the GPS locations of different vehicles inthe vehicle system. Differences in altitude, location, or the like,between two or more vehicles in the vehicle system can be used tocalculate or estimate the grade of the route, the curvature of theroute, or the like. For example, if two vehicles 904, 906 have differentaltitudes and are spaced apart by a designated or estimated distancewithin the vehicle system, then the grade of the route between thesevehicles 904, 906 may be determined or estimated. As another example,differences in geographic coordinates between two or more vehicles 904,906 and/or the separation distances between these vehicles 904, 906 canbe used to calculate or approximate the curvature of the route betweenthese vehicles 904, 906.

FIG. 13 illustrates a schematic diagram of a planning system 1300according to one embodiment. The planning system can be used to generatecommand profiles, position indices, and/or time indices for operation ofthe vehicle systems described herein. For example, the planning systemmay perform one or more operations of the methods described herein inorder to determine operational settings, vehicle group assignments,fence positions, potential change points along the route where thevehicle group assignments and/or fence positions are to change, or thelike.

Components of the planning system may include or represent hardwarecircuits or circuitry that include and/or are connected with one or moreprocessors, such as one or more computer microprocessors. The operationsof the methods described herein and the planning system can besufficiently complex such that the operations cannot be mentallyperformed by an average human being or a person of ordinary skill in theart within a commercially reasonable time period. For example, thegeneration of command profiles, position indices, and/or time indicesfor trips of vehicle systems may take into account a large amount offactors, may rely on relatively complex computations, may involveexamination of many permutations of different potential sequences, andthe like, such that such a person cannot complete the command profiles,position indices, and/or time indices within a commercially reasonabletime period to have the command profiles, position indices, and/or timeindices ready for the frequent trips of vehicle systems. The hardwarecircuits and/or processors of the planning system may be used tosignificantly reduce the time needed to determine the command profiles,position indices, and/or time indices such that these command profiles,position indices, and/or time indices can be generated withincommercially reasonable time periods.

The planning system may be located onboard a vehicle system, off-board avehicle system (e.g., at a dispatch center or other location), or mayhave some components disposed onboard a vehicle system and othercomponents disposed off-board the vehicle system. The planning systemincludes an input device 1302 that obtains data used to determine thecommand profiles, position indices, and/or time indices. The inputdevice can include a communication device, such as a wirelesstransceiver and associated hardware circuitry, a modem, or the like,that receives system data, vehicle data, route data, constraint data,trip plans (e.g., speed profiles), or the like, from an off-boardlocation. Optionally, the input device can include a keyboard,microphone, touchscreen, stylus, or the like, that can receive thisdata.

A memory device 1304 includes one or more computer readable storagemedia, such as computer hard drives, random access memory (RAM), dynamicRAM (DRAM), static RAM (SRAM), read only memory (ROM), mask ROM,programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM(EEPROM), non-volatile RAM (NVRAM), flash memory, magnetic tapes,optical discs, or the like. The memory device may store the data that isobtained by the input device, trip plans (e.g., speed profiles),designated potential change points along the route (e.g., potentialchange points), command profiles, position indices, time indices, or thelike. In one embodiment, the flowchart of the methods described hereincan represent one or more sets of instructions that are stored on thememory device for directing operations of the planning system.Alternatively, the memory device may have one or more other sets ofinstructions 1308 stored on the memory device (e.g., software) to directoperations of the planning system as described herein.

An output device 1306 generates signals that communicate information toa vehicle system, an operator of the vehicle system, or to anotherlocation. These signals may convey the command profiles, positionindices, and/or time indices determined by the planning system. Forexample, the output device can be the same or different communicationdevice as the input device in order to communicate this information toanother location. Optionally, the output device can include atouchscreen, display device, speaker, or the like, for communicating thecommand profiles, position indices, or other information. The outputdevice can communicate the command profiles, position indices, and/orother information to the vehicle system so that the vehicle system canpresent the command profiles, position indices, time indices, and/orother information to an operator to direct manual control of the vehiclesystem and/or to direct automatic control of the vehicle system.

The planning system includes one or more modeling processors 1310 thatmay include and/or represent hardware circuits or circuitry that includeand/or are connected with one or more processors, such as one or morecomputer microprocessors. The modeling processor optionally mayrepresent one or more sets of instructions stored on a computer readablemedium, such as one or more software applications. The modelingprocessor can perform various calculations described herein. Forexample, the modeling processor may determine the handling parameters(such as coupler forces), for different locations in the vehicle system,for different vehicle group assignments, for different fence positionsin the vehicle system, for different potential change points (e.g., meshpoints) of the vehicle system along the route, and the like, asdescribed above. The modeling processor can determine the bunching powermetrics, such as the bunching HP metrics, for different vehicle groupassignments, different fence positions and/or different potential changepoints of the vehicle system, as described above.

The planning system includes one or more sequencing processors 1312 thatmay include and/or represent hardware circuits or circuitry that includeand/or are connected with one or more processors, such as one or morecomputer microprocessors. In one embodiment, the one or more modelingprocessors and the one or more sequencing processors may be embodied inthe same computer processor or two or more computer processors. Thesequencing processor optionally may represent one or more sets ofinstructions stored on a computer readable medium, such as one or moresoftware applications. The sequencing processor can perform variousoperations described herein. For example, the sequencing processor canexamine the handling parameters determined by the modeling processor,determine potential sequences for changing the vehicle group assignmentsand/or moving the position and/or number of the fence(s) in the vehiclesystem, identify a selected sequence for changing the vehicle groupassignments and/or moving the fence, and the like, as described above.The sequencing processor optionally may identify the segments ofpotential change points along the route where the vehicle groupassignments and/or fence positions are the same and/or merge thesesegments to identify the selected sequence, also as described above. Thesequencing processor may use the selected sequence to generate thecommand profiles, position indices, and/or time indices that are outputby the output device to the vehicle system. As described above, thesecommand profiles and position indices can be used to control where andwhen the vehicle group assignments and/or fence positions are changedwithin the vehicle system.

In one embodiment, the planning system may determine command profiles,change indices, time indices, fence positions and/or number of fences,operational settings, or the like, based on and/or in coordination withinput from an operator of the vehicle system. The operator can provide apower request to the planning system via input provided to the inputdevice 1302. The processors 1310 and/or 1312 can then determineassignments of the vehicles to different groups, operational settings ofthe vehicles in the different groups, and/or the locations and/or timeswhere the groups and/or operational settings are to be used such thatthe vehicles provide at least the amount of power requested by theoperator (as indicated by the power request). In one aspect, theprocessors 1310 and/or 1312 can determine several different sets ofvehicle assignments to different groups, operational settings,locations, and/or times and present these different sets to the operatorvia the output device 1306. The operator may then select one or more ofthe sets via the input device 1302. The planning system may then createand/or modify a command profile and/or change indices to provide thepower requested by the operator and/or the set of vehicle assignments,operational settings, locations, and/or times selected by the operator.

In one aspect, the planning system can determine number of fences andthe positions of the fences at one or more locations and/or times alongthe route, but the operator selects the operational settings (e.g.,throttle notch positions, brake settings, or the like) for thesystem-determined fence settings. For example, at a first potentialchange point, the planning system may determine that a fence should bepositioned between the vehicles 904B and 906A. The planning system mayreport this fence position to the operator (e.g., via the output device1306). The operator may then select the operational settings to be usedby the vehicles 904A-B and the operational settings to be used by thevehicles 906A-D and/or the vehicles 904C-D for this fence position(e.g., via the input device 1302). Alternatively, the operator mayselect operational settings for one or more of the vehicles 904, 906 atone or more locations and/or times along the route during a trip of thevehicle system, and the planning system can determine fence positionsfor the vehicles at the locations and/or times.

The planning system may provide the operator with an ability to opt outor override the number of fences and/or the position of one or morefences, operational setting, or the like, that is determined by theplanning system. The planning system can inform the operator of thefence positions, operational settings, or the like, via the outputdevice 1306. The operator may reject the system-determined fenceposition, operational setting, or the like, via the input device 1302.The planning system may determine another fence position, operationalsetting, or the like, and/or the operator may provide anoperator-selected or operator-determined fence position, operationalsetting, or the like.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the inventivesubject matter without departing from its scope. While the dimensionsand types of materials described herein are intended to define theparameters of the inventive subject matter, they are by no meanslimiting and are exemplary embodiments. Many other embodiments will beapparent to one of ordinary skill in the art upon reviewing the abovedescription. The scope of the inventive subject matter should,therefore, be determined with reference to the appended clauses, alongwith the full scope of equivalents to which such clauses are entitled.In the appended clauses, the terms “including” and “in which” are usedas the plain-English equivalents of the respective terms “comprising”and “wherein.” Moreover, in the following clauses, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following clauses are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. §112(f), unless and until such clause limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure.

This written description uses examples to disclose several embodimentsof the inventive subject matter and also to enable a person of ordinaryskill in the art to practice the embodiments of the inventive subjectmatter, including making and using any devices or systems and performingany incorporated methods. The patentable scope of the inventive subjectmatter may include other examples that occur to those of ordinary skillin the art. Such other examples are intended to be within the scope ofthe clauses if they have structural elements that do not differ from theliteral language of the clauses, or if they include equivalentstructural elements with insubstantial differences from the literallanguages of the clauses.

The foregoing description of certain embodiments of the inventivesubject matter will be better understood when read in conjunction withthe appended drawings. To the extent that the figures illustratediagrams of the functional blocks of various embodiments, the functionalblocks are not necessarily indicative of the division between hardwarecircuitry. Thus, for example, one or more of the functional blocks (forexample, processors or memories) may be implemented in a single piece ofhardware (for example, a general purpose signal processor,microcontroller, random access memory, hard disk, and the like).Similarly, the programs may be stand-alone programs, may be incorporatedas subroutines in an operating system, may be functions in an installedsoftware package, and the like. The various embodiments are not limitedto the arrangements and instrumentality shown in the drawings.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “an embodiment” or “one embodiment” of theinventive subject matter are not intended to be interpreted as excludingthe existence of additional embodiments that also incorporate therecited features. Moreover, unless explicitly stated to the contrary,embodiments “comprising,” “including,” or “having” an element or aplurality of elements having a particular property may includeadditional such elements not having that property.

Since certain changes may be made in the above-described systems andmethods without departing from the spirit and scope of the inventivesubject matter herein involved, it is intended that all of the subjectmatter of the above description or shown in the accompanying drawingsshall be interpreted merely as examples illustrating the inventiveconcept herein and shall not be construed as limiting the inventivesubject matter.

As used herein, a structure, limitation, or element that is “configuredto” perform a task or operation is particularly structurally formed,constructed, programmed, or adapted in a manner corresponding to thetask or operation. For purposes of clarity and the avoidance of doubt,an object that is merely capable of being modified to perform the taskor operation is not “configured to” perform the task or operation asused herein. Instead, the use of “configured to” as used herein denotesstructural adaptations or characteristics, programming of the structureor element to perform the corresponding task or operation in a mannerthat is different from an “off-the-shelf” structure or element that isnot programmed to perform the task or operation, and/or denotesstructural requirements of any structure, limitation, or element that isdescribed as being “configured to” perform the task or operation.

What is claimed is:
 1. A method comprising: assigning plural vehicles ina vehicle system to different groups, the vehicle system including thevehicles operably coupled with each other to travel along a routetogether during a trip; determining operational settings for thevehicles in each of the different groups, the operational settingsdetermined to be concurrently implemented by the vehicles in thedifferent groups during movement of the vehicle system along the routeduring the trip; and modifying one or more of the groups to which thevehicles are assigned or the operational settings for the vehicles basedon a handling parameter of the vehicle system.
 2. The method of claim 1,wherein assigning the vehicles to the groups includes associating thevehicles with different groups without changing a physical position ofone or more of the vehicles within the vehicle system.
 3. The method ofclaim 1, wherein assigning the vehicles to the groups includes changinga physical position of one or more of the vehicles within the vehiclesystem.
 4. The method of claim 1, wherein assigning the vehicles to thegroups includes one or more of adding an additional vehicle to thevehicle system during travel along the route during the trip, removingat least one of the vehicles from the vehicle system during travel alongthe route during the trip, or separating the vehicle system into two ormore smaller vehicle systems during travel along the route during thetrip.
 5. The method of claim 1, wherein the operational settings thatare determined include one or more of throttle notch positions or brakesettings of the vehicles.
 6. The method of claim 1, wherein determiningthe operational settings includes determining different operationalsettings for the respective groups.
 7. The method of claim 1, whereindetermining the operational settings for the vehicles is performedwithout a previously generated synchronous trip plan that designatescommon operational settings for the vehicles in the vehicle system as afunction of one or more of time or distance along the route for thetrip.
 8. The method of claim 1, wherein the operational settings aredetermined to achieve a trip objective of the vehicle system for thetrip subject to one or more operating constraints on the vehicle system.9. The method of claim 8, wherein the trip objective includes one ormore of fuel use or emissions reduction, maintaining a balance of fuelcarried by the vehicles to within a designated range among the vehicles,or reducing a number of nodes in the vehicle system beneath a designatednumber.
 10. The method of claim 8, wherein the one or more operatingconstraints include one or more of an engine derating of one or more ofthe vehicles, a notch delta penalty that limits a change in theoperational settings of the vehicles, or group assignment restrictions.11. The method of claim 10, wherein the group assignment restrictionsinclude one or more of a limit on how frequently the groups to which thevehicles are assigned can change or a limit on a total number of groupsas a function of time, location, or operator input.
 12. The method ofclaim 1, wherein the handling parameter represents one or more of aforce exerted on one or more couplers between the vehicles in thevehicle system, an energy stored in the one or more couplers, relativevelocities of neighboring vehicles of the vehicles in the vehiclesystem, a natural force exerted on one or more of the vehicles in thevehicle system that are disposed between propulsion-generating vehiclesof the vehicles in the vehicle system, or momentum of one or more of thevehicles in the vehicle system.
 13. The method of claim 12, furthercomprising determining the handling parameter based on one or more ofmeasuring the force exerted on the one or more couplers, measuring aseparation distance between two or more vehicles of the vehicle system,determining kinetic energy and potential energy of at least one of thevehicles of the vehicle system, or determining locations of two or moreof the vehicles in the vehicle system.
 14. The method of claim 12,wherein the handling parameter that is determined includes the momentumof the one or more vehicles in the vehicle system, wherein determiningthe operational settings includes determining the operational settingssuch that the momentum of the one or more vehicles in the vehicle systemis changed to be within a designated range of a momentum of one or moreother vehicles in the vehicle system.
 15. The method of claim 1, whereinassigning the vehicles in the vehicle system to the groups is performedwith a non-even distribution of weight of the vehicles in the vehiclesystem.
 16. The method of claim 1, further comprising receiving a powerrequest from an operator for an amount of tractive power to be providedby the vehicle system, wherein one or more of assigning the vehicles tothe groups or determining the operational settings is performed based onthe power request that is received.
 17. The method of claim 1, furthercomprising communicating a recommended assignment of the vehicles to thegroups to an operator of the vehicle system and receiving theoperational settings from the operator.
 18. The method of claim 1,further comprising communicating recommended operational settings forthe vehicles to an operator of the vehicle system and receiving anassignment of the vehicles to the groups from the operator.
 19. Themethod of claim 1, wherein assigning the vehicles to the groups includesdetermining the handling parameter of the vehicle system for allpermutations of assignments of the vehicles to the groups and assigningthe vehicles to the groups based on the handling parameters associatedwith the permutations of assignments.
 20. The method of claim 1, whereinassigning the vehicles to the groups includes determining the handlingparameter of the vehicle system for less than all permutations ofassignments of the vehicles to the groups and assigning the vehicles tothe groups based on the handling parameters associated with thepermutations of assignments, wherein the handling parameters are notdetermined for the permutations of assignments that include one or moreof changing the assignments of the vehicles to the groups more oftenthan a first designated limit or changing the operational settings ofone or more of the vehicles by an amount that is larger than a seconddesignated limit.
 21. The method of claim 1, wherein assigning thevehicles to the groups and determining the operational settings isperformed for an entire duration of the trip prior to departure of thevehicle system for the trip.
 22. The method of claim 1, whereinassigning the vehicles to the groups and determining the operationalsettings includes determining the handling parameter for the groups atdifferent locations along the route and selecting a sequence of changesto assignments of the vehicles to the groups that changes the handlingparameter by at least a designated amount over one or more of adesignated period of time or distance along the route following a changeto the assignments of the vehicles to the groups.
 23. The method ofclaim 1, wherein assigning the vehicles to the groups includes assigningthe vehicles to a restricted number of the groups of vehicles.
 24. Themethod of claim 1, wherein assigning the vehicles to the groups anddetermining the operational settings is performed prior to departure ofthe vehicle system for the trip.
 25. A system comprising: one or moreprocessors configured to assign plural vehicles in a vehicle system todifferent groups, the vehicle system including the vehicles operablycoupled with each other to travel along a route together during a trip,the one or more processors also configured to determine operationalsettings for the vehicles in the different groups, the operationalsettings determined by the one or more processors to be concurrentlyimplemented by the vehicles in the different groups during movement ofthe vehicle system along the route during the trip, wherein the one ormore processors also are configured to modify one or more of the groupsto which the vehicles are assigned or the operational settings for thevehicles based on a handling parameter of the vehicle system.
 26. Amethod comprising: assigning plural vehicles in a vehicle system todifferent groups, the vehicle system including the vehicles operablycoupled with each other to travel along a route together during a trip,wherein a total number of the groups to which the vehicles are assignedis limited based on a location of the vehicle system along the route, atime at which the vehicles are assigned to the groups, or input from anoperator of the vehicle system; determining operational settings for thevehicles in the different groups, the operational settings determined tobe concurrently implemented by the vehicles in the different groupsduring movement of the vehicle system along the route during the trip;and modifying one or more of the groups to which the vehicles areassigned or the operational settings for the vehicles based on ahandling parameter of the vehicle system.